luceos I tried again to uninstall and reinstall the extension.
After that I clicked on this icon:

And got the following error (I did not find any mention of this extension in the database):


{
  "errors": [
    {
      "status": "500",
      "code": "unknown",
      "detail": "PDOException: SQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP 'best_answer_set_at'; check that column/key exists in /var/www/remonk_u/data/www/remonk.ru/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php:127\nStack trace:\n#0 /var/www/remonk_u/data/www/remonk.ru/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php(127): PDOStatement->execute(NULL)\n#1 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php(458): Doctrine\\DBAL\\Driver\\PDOStatement->execute()\n#2 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php(657): Illuminate\\Database\\Connection->Illuminate\\Database\\{closure}('alter table `re...', Array)\n#3 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php(624): Illuminate\\Database\\Connection->runQueryCallback('alter table `re...', Array, Object(Closure))\n#4 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php(459): Illuminate\\Database\\Connection->run('alter table `re...', Array, Object(Closure))\n#5 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Schema/Blueprint.php(97): Illuminate\\Database\\Connection->statement('alter table `re...')\n#6 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Schema/Builder.php(264): Illuminate\\Database\\Schema\\Blueprint->build(Object(Illuminate\\Database\\MySqlConnection), Object(Illuminate\\Database\\Schema\\Grammars\\MySqlGrammar))\n#7 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Schema/Builder.php(149): Illuminate\\Database\\Schema\\Builder->build(Object(Illuminate\\Database\\Schema\\Blueprint))\n#8 /var/www/remonk_u/data/www/remonk.ru/vendor/fof/best-answer/migrations/2020_02_04_205300_add_best_answer_set_timestamp.php(28): Illuminate\\Database\\Schema\\Builder->table('discussions', Object(Closure))\n#9 [internal function]: Illuminate\\Filesystem\\Filesystem->{closure}(Object(Illuminate\\Database\\Schema\\MySqlBuilder))\n#10 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Database/Migrator.php(197): call_user_func(Object(Closure), Object(Illuminate\\Database\\Schema\\MySqlBuilder))\n#11 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Database/Migrator.php(177): Flarum\\Database\\Migrator->runClosureMigration(Array, 'down')\n#12 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Database/Migrator.php(157): Flarum\\Database\\Migrator->runDown('/var/www/remonk...', '2020_02_04_2053...', Object(Flarum\\Extension\\Extension))\n#13 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/Extension.php(354): Flarum\\Database\\Migrator->reset('/var/www/remonk...', Object(Flarum\\Extension\\Extension))\n#14 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/ExtensionManager.php(246): Flarum\\Extension\\Extension->migrate(Object(Flarum\\Database\\Migrator), 'down')\n#15 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/ExtensionManager.php(257): Flarum\\Extension\\ExtensionManager->migrate(Object(Flarum\\Extension\\Extension), 'down')\n#16 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/ExtensionManager.php(187): Flarum\\Extension\\ExtensionManager->migrateDown(Object(Flarum\\Extension\\Extension))\n#17 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Api/Controller/UninstallExtensionController.php(44): Flarum\\Extension\\ExtensionManager->uninstall('fof-best-answer')\n#18 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Api/Controller/AbstractDeleteController.php(24): Flarum\\Api\\Controller\\UninstallExtensionController->delete(Object(Laminas\\Diactoros\\ServerRequest))\n#19 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/RouteHandlerFactory.php(38): Flarum\\Api\\Controller\\AbstractDeleteController->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#20 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/DispatchRoute.php(65): Flarum\\Http\\RouteHandlerFactory->Flarum\\Http\\{closure}(Object(Laminas\\Diactoros\\ServerRequest), Array)\n#21 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\DispatchRoute->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Closure))\n#22 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/SetLocale.php(50): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#23 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\SetLocale->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#24 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/CheckCsrfToken.php(45): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#25 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\CheckCsrfToken->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#26 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/AuthenticateWithHeader.php(55): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#27 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\AuthenticateWithHeader->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#28 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/AuthenticateWithSession.php(32): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#29 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\AuthenticateWithSession->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#30 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/RememberFromCookie.php(51): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#31 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\RememberFromCookie->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#32 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/StartSession.php(61): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#33 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\StartSession->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#34 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Api/Middleware/FakeHttpMethods.php(29): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#35 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Api\\Middleware\\FakeHttpMethods->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#36 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/ParseJsonBody.php(28): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#37 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\ParseJsonBody->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#38 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/HandleErrors.php(57): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#39 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\HandleErrors->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#40 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(84): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#41 /var/www/remonk_u/data/www/remonk.ru/vendor/middlewares/request-handler/src/RequestHandler.php(84): Laminas\\Stratigility\\MiddlewarePipe->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#42 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Middlewares\\RequestHandler->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#43 /var/www/remonk_u/data/www/remonk.ru/vendor/middlewares/base-path-router/src/BasePathRouter.php(97): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#44 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Middlewares\\BasePathRouter->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#45 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Middleware/OriginalMessages.php(42): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#46 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Laminas\\Stratigility\\Middleware\\OriginalMessages->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#47 /var/www/remonk_u/data/www/remonk.ru/vendor/middlewares/base-path/src/BasePath.php(53): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#48 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Middlewares\\BasePath->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#49 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(84): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#50 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(73): Laminas\\Stratigility\\MiddlewarePipe->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\EmptyPipelineHandler))\n#51 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-httphandlerrunner/src/RequestHandlerRunner.php(96): Laminas\\Stratigility\\MiddlewarePipe->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#52 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Server.php(42): Laminas\\HttpHandlerRunner\\RequestHandlerRunner->run()\n#53 /var/www/remonk_u/data/www/remonk.ru/public/index.php(26): Flarum\\Http\\Server->listen()\n#54 {main}\n\nNext Doctrine\\DBAL\\Driver\\PDOException: SQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP 'best_answer_set_at'; check that column/key exists in /var/www/remonk_u/data/www/remonk.ru/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php:129\nStack trace:\n#0 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php(458): Doctrine\\DBAL\\Driver\\PDOStatement->execute()\n#1 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php(657): Illuminate\\Database\\Connection->Illuminate\\Database\\{closure}('alter table `re...', Array)\n#2 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php(624): Illuminate\\Database\\Connection->runQueryCallback('alter table `re...', Array, Object(Closure))\n#3 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php(459): Illuminate\\Database\\Connection->run('alter table `re...', Array, Object(Closure))\n#4 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Schema/Blueprint.php(97): Illuminate\\Database\\Connection->statement('alter table `re...')\n#5 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Schema/Builder.php(264): Illuminate\\Database\\Schema\\Blueprint->build(Object(Illuminate\\Database\\MySqlConnection), Object(Illuminate\\Database\\Schema\\Grammars\\MySqlGrammar))\n#6 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Schema/Builder.php(149): Illuminate\\Database\\Schema\\Builder->build(Object(Illuminate\\Database\\Schema\\Blueprint))\n#7 /var/www/remonk_u/data/www/remonk.ru/vendor/fof/best-answer/migrations/2020_02_04_205300_add_best_answer_set_timestamp.php(28): Illuminate\\Database\\Schema\\Builder->table('discussions', Object(Closure))\n#8 [internal function]: Illuminate\\Filesystem\\Filesystem->{closure}(Object(Illuminate\\Database\\Schema\\MySqlBuilder))\n#9 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Database/Migrator.php(197): call_user_func(Object(Closure), Object(Illuminate\\Database\\Schema\\MySqlBuilder))\n#10 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Database/Migrator.php(177): Flarum\\Database\\Migrator->runClosureMigration(Array, 'down')\n#11 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Database/Migrator.php(157): Flarum\\Database\\Migrator->runDown('/var/www/remonk...', '2020_02_04_2053...', Object(Flarum\\Extension\\Extension))\n#12 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/Extension.php(354): Flarum\\Database\\Migrator->reset('/var/www/remonk...', Object(Flarum\\Extension\\Extension))\n#13 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/ExtensionManager.php(246): Flarum\\Extension\\Extension->migrate(Object(Flarum\\Database\\Migrator), 'down')\n#14 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/ExtensionManager.php(257): Flarum\\Extension\\ExtensionManager->migrate(Object(Flarum\\Extension\\Extension), 'down')\n#15 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/ExtensionManager.php(187): Flarum\\Extension\\ExtensionManager->migrateDown(Object(Flarum\\Extension\\Extension))\n#16 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Api/Controller/UninstallExtensionController.php(44): Flarum\\Extension\\ExtensionManager->uninstall('fof-best-answer')\n#17 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Api/Controller/AbstractDeleteController.php(24): Flarum\\Api\\Controller\\UninstallExtensionController->delete(Object(Laminas\\Diactoros\\ServerRequest))\n#18 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/RouteHandlerFactory.php(38): Flarum\\Api\\Controller\\AbstractDeleteController->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#19 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/DispatchRoute.php(65): Flarum\\Http\\RouteHandlerFactory->Flarum\\Http\\{closure}(Object(Laminas\\Diactoros\\ServerRequest), Array)\n#20 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\DispatchRoute->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Closure))\n#21 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/SetLocale.php(50): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#22 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\SetLocale->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#23 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/CheckCsrfToken.php(45): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#24 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\CheckCsrfToken->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#25 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/AuthenticateWithHeader.php(55): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#26 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\AuthenticateWithHeader->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#27 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/AuthenticateWithSession.php(32): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#28 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\AuthenticateWithSession->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#29 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/RememberFromCookie.php(51): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#30 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\RememberFromCookie->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#31 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/StartSession.php(61): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#32 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\StartSession->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#33 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Api/Middleware/FakeHttpMethods.php(29): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#34 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Api\\Middleware\\FakeHttpMethods->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#35 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/ParseJsonBody.php(28): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#36 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\ParseJsonBody->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#37 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/HandleErrors.php(57): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#38 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\HandleErrors->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#39 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(84): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#40 /var/www/remonk_u/data/www/remonk.ru/vendor/middlewares/request-handler/src/RequestHandler.php(84): Laminas\\Stratigility\\MiddlewarePipe->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#41 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Middlewares\\RequestHandler->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#42 /var/www/remonk_u/data/www/remonk.ru/vendor/middlewares/base-path-router/src/BasePathRouter.php(97): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#43 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Middlewares\\BasePathRouter->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#44 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Middleware/OriginalMessages.php(42): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#45 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Laminas\\Stratigility\\Middleware\\OriginalMessages->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#46 /var/www/remonk_u/data/www/remonk.ru/vendor/middlewares/base-path/src/BasePath.php(53): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#47 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Middlewares\\BasePath->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#48 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(84): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#49 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(73): Laminas\\Stratigility\\MiddlewarePipe->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\EmptyPipelineHandler))\n#50 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-httphandlerrunner/src/RequestHandlerRunner.php(96): Laminas\\Stratigility\\MiddlewarePipe->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#51 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Server.php(42): Laminas\\HttpHandlerRunner\\RequestHandlerRunner->run()\n#52 /var/www/remonk_u/data/www/remonk.ru/public/index.php(26): Flarum\\Http\\Server->listen()\n#53 {main}\n\nNext Illuminate\\Database\\QueryException: SQLSTATE[42000]: Syntax error or access violation: 1091 Can't DROP 'best_answer_set_at'; check that column/key exists (SQL: alter table `re_discussions` drop `best_answer_set_at`) in /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php:664\nStack trace:\n#0 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php(624): Illuminate\\Database\\Connection->runQueryCallback('alter table `re...', Array, Object(Closure))\n#1 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Connection.php(459): Illuminate\\Database\\Connection->run('alter table `re...', Array, Object(Closure))\n#2 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Schema/Blueprint.php(97): Illuminate\\Database\\Connection->statement('alter table `re...')\n#3 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Schema/Builder.php(264): Illuminate\\Database\\Schema\\Blueprint->build(Object(Illuminate\\Database\\MySqlConnection), Object(Illuminate\\Database\\Schema\\Grammars\\MySqlGrammar))\n#4 /var/www/remonk_u/data/www/remonk.ru/vendor/illuminate/database/Schema/Builder.php(149): Illuminate\\Database\\Schema\\Builder->build(Object(Illuminate\\Database\\Schema\\Blueprint))\n#5 /var/www/remonk_u/data/www/remonk.ru/vendor/fof/best-answer/migrations/2020_02_04_205300_add_best_answer_set_timestamp.php(28): Illuminate\\Database\\Schema\\Builder->table('discussions', Object(Closure))\n#6 [internal function]: Illuminate\\Filesystem\\Filesystem->{closure}(Object(Illuminate\\Database\\Schema\\MySqlBuilder))\n#7 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Database/Migrator.php(197): call_user_func(Object(Closure), Object(Illuminate\\Database\\Schema\\MySqlBuilder))\n#8 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Database/Migrator.php(177): Flarum\\Database\\Migrator->runClosureMigration(Array, 'down')\n#9 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Database/Migrator.php(157): Flarum\\Database\\Migrator->runDown('/var/www/remonk...', '2020_02_04_2053...', Object(Flarum\\Extension\\Extension))\n#10 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/Extension.php(354): Flarum\\Database\\Migrator->reset('/var/www/remonk...', Object(Flarum\\Extension\\Extension))\n#11 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/ExtensionManager.php(246): Flarum\\Extension\\Extension->migrate(Object(Flarum\\Database\\Migrator), 'down')\n#12 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/ExtensionManager.php(257): Flarum\\Extension\\ExtensionManager->migrate(Object(Flarum\\Extension\\Extension), 'down')\n#13 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Extension/ExtensionManager.php(187): Flarum\\Extension\\ExtensionManager->migrateDown(Object(Flarum\\Extension\\Extension))\n#14 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Api/Controller/UninstallExtensionController.php(44): Flarum\\Extension\\ExtensionManager->uninstall('fof-best-answer')\n#15 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Api/Controller/AbstractDeleteController.php(24): Flarum\\Api\\Controller\\UninstallExtensionController->delete(Object(Laminas\\Diactoros\\ServerRequest))\n#16 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/RouteHandlerFactory.php(38): Flarum\\Api\\Controller\\AbstractDeleteController->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#17 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/DispatchRoute.php(65): Flarum\\Http\\RouteHandlerFactory->Flarum\\Http\\{closure}(Object(Laminas\\Diactoros\\ServerRequest), Array)\n#18 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\DispatchRoute->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Closure))\n#19 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/SetLocale.php(50): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#20 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\SetLocale->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#21 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/CheckCsrfToken.php(45): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#22 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\CheckCsrfToken->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#23 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/AuthenticateWithHeader.php(55): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#24 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\AuthenticateWithHeader->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#25 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/AuthenticateWithSession.php(32): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#26 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\AuthenticateWithSession->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#27 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/RememberFromCookie.php(51): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#28 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\RememberFromCookie->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#29 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/StartSession.php(61): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#30 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\StartSession->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#31 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Api/Middleware/FakeHttpMethods.php(29): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#32 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Api\\Middleware\\FakeHttpMethods->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#33 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/ParseJsonBody.php(28): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#34 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\ParseJsonBody->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#35 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Middleware/HandleErrors.php(57): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#36 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Flarum\\Http\\Middleware\\HandleErrors->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#37 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(84): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#38 /var/www/remonk_u/data/www/remonk.ru/vendor/middlewares/request-handler/src/RequestHandler.php(84): Laminas\\Stratigility\\MiddlewarePipe->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#39 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Middlewares\\RequestHandler->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#40 /var/www/remonk_u/data/www/remonk.ru/vendor/middlewares/base-path-router/src/BasePathRouter.php(97): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#41 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Middlewares\\BasePathRouter->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#42 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Middleware/OriginalMessages.php(42): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#43 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Laminas\\Stratigility\\Middleware\\OriginalMessages->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#44 /var/www/remonk_u/data/www/remonk.ru/vendor/middlewares/base-path/src/BasePath.php(53): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#45 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/Next.php(61): Middlewares\\BasePath->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\Next))\n#46 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(84): Laminas\\Stratigility\\Next->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#47 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(73): Laminas\\Stratigility\\MiddlewarePipe->process(Object(Laminas\\Diactoros\\ServerRequest), Object(Laminas\\Stratigility\\EmptyPipelineHandler))\n#48 /var/www/remonk_u/data/www/remonk.ru/vendor/laminas/laminas-httphandlerrunner/src/RequestHandlerRunner.php(96): Laminas\\Stratigility\\MiddlewarePipe->handle(Object(Laminas\\Diactoros\\ServerRequest))\n#49 /var/www/remonk_u/data/www/remonk.ru/vendor/flarum/core/src/Http/Server.php(42): Laminas\\HttpHandlerRunner\\RequestHandlerRunner->run()\n#50 /var/www/remonk_u/data/www/remonk.ru/public/index.php(26): Flarum\\Http\\Server->listen()\n#51 {main}"
    }`

    Aleram that buttons seems to remove related database tables and rows (thanks @datitisev for confirming). That it causes errors isn't great, but it is unrelated to your issue.

    Truth be told I am running out of ideas, what I would like to know if this same issue occurs on a different hosting environment. Most likely the answer will show that it is isolated to your server (otherwise we would have heard more complaints).

    With that in mind, I cannot offer any other advice.

    I'll try and remember to revisit this issue after beta 14. Right now the focus is on that. I know I've seen other people have the same issue with the validation, but I haven't investigated far enough to say whether I am stumped or not.

    2 months later

    Hello, I have the same problem.

    Flarum core 0.1.0-beta.14.1
    Fof-best-answer version: 0.2.0
    PHP version: 7.4.11

    code: "validation_error"
    detail: "Selected post does not exist in this discussion"
    source: Object { pointer: "/data/attributes/error" }
    status: "422"

    Do you have a solution ? I am on PlanetHoster.

      a month later

      theportablegeek EvilExecutor SvenSeitan Aleram

      Purely a hunch, but can you please try composer require fof/best-answer:dev-master to see if your issue is resolved?

      If not, please let me know your DB type (MySQL, MariaDB, Percona, etc), version and PHP version so I can dig deeper with this 🙂

        IanM not a solution for me 🙁 and its strange because everything runs super smoothly on localhost

        In terms of the version which is NOT working for me, it is running on Shared Hosting with the following setup:

        Database Server

        Server: Localhost via UNIX socket
        Server type: MariaDB
        Server connection: SSL is not being used Documentation
        Server version: 10.3.27-MariaDB-log-cll-lve - MariaDB Server
        Protocol version: 10
        Server charset: cp1252 West European (latin1)

        Web Server

        cpsrvd 11.92.0.6
        Database client version: libmysql - 5.6.43
        PHP extension: mysqli curl mbstring
        PHP version: 7.3.6

        In terms of the version which is working for me, it is running on Local Hosting with the following setup:

        Database Server

        Server: localhost via TCP/IP
        Server type: MySQL
        Server connection: SSL is not being used Documentation
        Server version: 5.7.24 - MySQL Community Server (GPL)
        Protocol version: 10
        User: root@localhost
        Server charset: UTF-8 Unicode (utf8)

        Web Server

        Apache/2.4.35 (Win64) OpenSSL/1.1.1a PHP/7.3.2
        Database client version: libmysql - mysqlnd 5.0.12-dev 
        PHP extension: mysqli curl mbstring
        PHP version: 7.3.2
        • IanM replied to this.

          theportablegeek thank you for that info.

          I've just pushed one more tiny change, just on the off chance, so if you could try the same composer command again and test, I'd really appreciate it. If not, I will spin up a local MariaDB/PHP 7.3/Flarum instance tomorrow and see what I can discover..

            IanM alas it did not work for me 🙁

            Thanks for your help on trying to sort this out 🙂

            • IanM replied to this.

              theportablegeek Thanks for your help on trying to sort this out

              No problem!

              theportablegeek alas it did not work for me

              Ok, so I don't seem to be able to replicate this issue, even when setting up a similar environment to yours. Instead, I've added some extra debug output to the validation output temporarily.

              Sorry to keep asking you this, but please can you:

              • composer require fof/best-answer:dev-master
              • php flarum cache:clear
              • Enable debug mode on your forum
              • Attempt to set a best answer
              • Share the validation debug output with me

              Thank you in advance for helping to solve this issue!

                IanM Thanks for this 🙂

                Here is what I get after following those steps:

                In the Pop-up Modal

                422 No Reason Phrase
                POST https://******.ca/api/discussions/333
                Selected post does not exist in this discussion. Debug: Request Post ID - {3696}, Post ID - {3696}, Post Discussion ID - {333}, Discussion ID - {333}

                In the Console Logs

                POST https://******.ca/api/discussions/333 422 Application.js:406:20
                Selected post does not exist in this discussion. Debug: Request Post ID - {3696}, Post ID - {3696}, Post Discussion ID - {333}, Discussion ID - {333} Application.js:408:12
                    request Application.js:408
                    (Async: promise callback)
                    request Application.js:352
                    save Model.js:159
                    a addBestAnswerAction.js:26
                    onclick addBestAnswerAction.js:66
                    handleEvent render.js:888
                Cookie “PHPSESSID” will be soon treated as cross-site cookie against “https://********.ca/api/discussions/333” because the scheme does not match. 333
                Uncaught (in promise) 
                Object { status: 422, options: {…}, xhr: XMLHttpRequest, responseText: "{\"errors\":[{\"status\":\"422\",\"code\":\"validation_error\",\"detail\":\"Selected post does not exist in this discussion. Debug: Request Post ID - {3696}, Post ID - {3696}, Post Discussion ID - {333}, Discussion ID - {333}\",\"source\":{\"pointer\":\"\\/data\\/attributes\\/error\"}}]}", response: {…}, alert: {…} }

                IanM interesting fact, if I comment out the validations in

                best-answer/src/Listeners/SelectBestAnswer.php

                Everything works fine, but only if I comment out both.

                @theportablegeek has almost explained everything... But I'm sure the problem is not caused due to the Database Server, PHP Version or Extensions. It also cannot be something related to Shared Hosting because the original author of this Discussion is using a VPS 😕

                Note: Even I cannot reproduce the issue on Local Host... Tried a couple of times.