Class "DOMDocument" not found

flruser

Hi there,

I'm getting this error when installing Flarum for the first time on an Ubuntu 22.04 with Nginx, GC infra. Can you please help?

I tried:

upgrading libxml2
reinstalling PHP

html/forum$ php flarum cache:clear -vvv
Clearing the cache...
html/forum$ sudo -u www-data php flarum cache:clear
Clearing the cache...
Could not clear contents of storage/cache. Please adjust file permissions and try again. This can frequently be fixed by clearing cache via the Tools dropdown on the Administration Dashboard page.

[2023-07-06 17:04:01] flarum.ERROR: Error: Class "DOMDocument" not found in /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/Helpers/TemplateLoader.php:142
Stack trace:
#0 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/Helpers/TemplateLoader.php(52): s9e\TextFormatter\Configurator\Helpers\TemplateLoader::loadAsXML()
#1 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/Helpers/TemplateInspector.php(149): s9e\TextFormatter\Configurator\Helpers\TemplateLoader::load()
#2 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/RulesGenerators/EnforceContentModels.php(38): s9e\TextFormatter\Configurator\Helpers\TemplateInspector->construct()
#3 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/Collections/RulesGeneratorList.php(30): s9e\TextFormatter\Configurator\RulesGenerators\EnforceContentModels->construct()
#4 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/Collections/NormalizedList.php(36): s9e\TextFormatter\Configurator\Collections\RulesGeneratorList->normalizeValue()
#5 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/RulesGenerator.php(70): s9e\TextFormatter\Configurator\Collections\NormalizedList->append()
#6 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator.php(129): s9e\TextFormatter\Configurator\RulesGenerator->construct()
#7 /var/www/html/forum/vendor/flarum/core/src/Formatter/Formatter.php(158): s9e\TextFormatter\Configurator->construct()
#8 /var/www/html/forum/vendor/flarum/core/src/Formatter/Formatter.php(213): Flarum\Formatter\Formatter->getConfigurator()
#9 /var/www/html/forum/vendor/illuminate/cache/Repository.php(426): Flarum\Formatter\Formatter->Flarum\Formatter{closure}()
#10 /var/www/html/forum/vendor/flarum/core/src/Formatter/Formatter.php(212): Illuminate\Cache\Repository->rememberForever()
#11 /var/www/html/forum/vendor/flarum/core/src/Formatter/Formatter.php(257): Flarum\Formatter\Formatter->getComponent()
#12 /var/www/html/forum/vendor/flarum/core/src/Forum/ForumServiceProvider.php(112): Flarum\Formatter\Formatter->getJs()
#13 [internal function]: Flarum\Forum\ForumServiceProvider->Flarum\Forum{closure}()
#14 /var/www/html/forum/vendor/flarum/core/src/Frontend/Compiler/Source/StringSource.php(38): call_user_func()
#15 /var/www/html/forum/vendor/flarum/core/src/Frontend/Compiler/Source/StringSource.php(49): Flarum\Frontend\Compiler\Source\StringSource->getContent()
#16 /var/www/html/forum/vendor/flarum/core/src/Frontend/Compiler/RevisionCompiler.php(174): Flarum\Frontend\Compiler\Source\StringSource->getCacheDifferentiator()
#17 /var/www/html/forum/vendor/flarum/core/src/Frontend/Compiler/RevisionCompiler.php(71): Flarum\Frontend\Compiler\RevisionCompiler->calculateRevision()
#18 /var/www/html/forum/vendor/flarum/core/src/Frontend/Compiler/RevisionCompiler.php(111): Flarum\Frontend\Compiler\RevisionCompiler->commit()
#19 /var/www/html/forum/vendor/flarum/core/src/Frontend/Content/Assets.php(118): Flarum\Frontend\Compiler\RevisionCompiler->getUrl()
#20 [internal function]: Flarum\Frontend\Content\Assets->Flarum\Frontend\Content{closure}()
#21 /var/www/html/forum/vendor/flarum/core/src/Frontend/Content/Assets.php(117): array_map()
#22 /var/www/html/forum/vendor/flarum/core/src/Frontend/Content/Assets.php(92): Flarum\Frontend\Content\Assets->getUrls()
#23 /var/www/html/forum/vendor/flarum/core/src/Frontend/Content/Assets.php(66): Flarum\Frontend\Content\Assets->addAssetsToDocument()
#24 /var/www/html/forum/vendor/flarum/core/src/Frontend/Frontend.php(62): Flarum\Frontend\Content\Assets->invoke()
#25 /var/www/html/forum/vendor/flarum/core/src/Frontend/Frontend.php(54): Flarum\Frontend\Frontend->populate()
#26 /var/www/html/forum/vendor/flarum/core/src/Frontend/Controller.php(32): Flarum\Frontend\Frontend->document()
#27 /var/www/html/forum/vendor/flarum/core/src/Http/RouteHandlerFactory.php(41): Flarum\Frontend\Controller->handle()
#28 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ExecuteRoute.php(27): Flarum\Http\RouteHandlerFactory->Flarum\Http{closure}()
#29 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ExecuteRoute->process()
#30 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ContentTypeOptionsHeader.php(21): Laminas\Stratigility\Next->handle()
#31 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ContentTypeOptionsHeader->process()
#32 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ReferrerPolicyHeader.php(30): Laminas\Stratigility\Next->handle()
#33 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ReferrerPolicyHeader->process()
#34 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/FlarumPromotionHeader.php(30): Laminas\Stratigility\Next->handle()
#35 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\FlarumPromotionHeader->process()
#36 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ShareErrorsFromSession.php(57): Laminas\Stratigility\Next->handle()
#37 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ShareErrorsFromSession->process()
#38 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/CheckCsrfToken.php(36): Laminas\Stratigility\Next->handle()
#39 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\CheckCsrfToken->process()
#40 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ResolveRoute.php(69): Laminas\Stratigility\Next->handle()
#41 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ResolveRoute->process()
#42 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/SetLocale.php(51): Laminas\Stratigility\Next->handle()
#43 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\SetLocale->process()
#44 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/AuthenticateWithSession.php(31): Laminas\Stratigility\Next->handle()
#45 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\AuthenticateWithSession->process()
#46 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/RememberFromCookie.php(52): Laminas\Stratigility\Next->handle()
#47 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\RememberFromCookie->process()
#48 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/StartSession.php(61): Laminas\Stratigility\Next->handle()
#49 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\StartSession->process()
#50 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/CollectGarbage.php(46): Laminas\Stratigility\Next->handle()
#51 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\CollectGarbage->process()
#52 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ParseJsonBody.php(28): Laminas\Stratigility\Next->handle()
#53 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ParseJsonBody->process()
#54 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/HandleErrors.php(57): Laminas\Stratigility\Next->handle()
#55 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\HandleErrors->process()
#56 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/InjectActorReference.php(25): Laminas\Stratigility\Next->handle()
#57 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\InjectActorReference->process()
#58 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(75): Laminas\Stratigility\Next->handle()
#59 /var/www/html/forum/vendor/middlewares/request-handler/src/RequestHandler.php(84): Laminas\Stratigility\MiddlewarePipe->process()
#60 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Middlewares\RequestHandler->process()
#61 /var/www/html/forum/vendor/middlewares/base-path-router/src/BasePathRouter.php(99): Laminas\Stratigility\Next->handle()
#62 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Middlewares\BasePathRouter->process()
#63 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Middleware/OriginalMessages.php(36): Laminas\Stratigility\Next->handle()
#64 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Laminas\Stratigility\Middleware\OriginalMessages->process()
#65 /var/www/html/forum/vendor/middlewares/base-path/src/BasePath.php(73): Laminas\Stratigility\Next->handle()
#66 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Middlewares\BasePath->process()
#67 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ProcessIp.php(24): Laminas\Stratigility\Next->handle()
#68 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ProcessIp->process()
#69 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(75): Laminas\Stratigility\Next->handle()
#70 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(64): Laminas\Stratigility\MiddlewarePipe->process()
#71 /var/www/html/forum/vendor/laminas/laminas-httphandlerrunner/src/RequestHandlerRunner.php(73): Laminas\Stratigility\MiddlewarePipe->handle()
#72 /var/www/html/forum/vendor/flarum/core/src/Http/Server.php(45): Laminas\HttpHandlerRunner\RequestHandlerRunner->run()
#73 /var/www/html/forum/index.php(26): Flarum\Http\Server->listen()
#74 {main}
[2023-07-06 17:08:37] flarum.ERROR: Error: Class "DOMDocument" not found in /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/Helpers/TemplateLoader.php:142
Stack trace:
#0 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/Helpers/TemplateLoader.php(52): s9e\TextFormatter\Configurator\Helpers\TemplateLoader::loadAsXML()
#1 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/Helpers/TemplateInspector.php(149): s9e\TextFormatter\Configurator\Helpers\TemplateLoader::load()
#2 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/RulesGenerators/EnforceContentModels.php(38): s9e\TextFormatter\Configurator\Helpers\TemplateInspector->construct()
#3 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/Collections/RulesGeneratorList.php(30): s9e\TextFormatter\Configurator\RulesGenerators\EnforceContentModels->construct()
#4 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/Collections/NormalizedList.php(36): s9e\TextFormatter\Configurator\Collections\RulesGeneratorList->normalizeValue()
#5 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator/RulesGenerator.php(70): s9e\TextFormatter\Configurator\Collections\NormalizedList->append()
#6 /var/www/html/forum/vendor/s9e/text-formatter/src/Configurator.php(129): s9e\TextFormatter\Configurator\RulesGenerator->construct()
#7 /var/www/html/forum/vendor/flarum/core/src/Formatter/Formatter.php(158): s9e\TextFormatter\Configurator->construct()
#8 /var/www/html/forum/vendor/flarum/core/src/Formatter/Formatter.php(213): Flarum\Formatter\Formatter->getConfigurator()
#9 /var/www/html/forum/vendor/illuminate/cache/Repository.php(426): Flarum\Formatter\Formatter->Flarum\Formatter{closure}()
#10 /var/www/html/forum/vendor/flarum/core/src/Formatter/Formatter.php(212): Illuminate\Cache\Repository->rememberForever()
#11 /var/www/html/forum/vendor/flarum/core/src/Formatter/Formatter.php(257): Flarum\Formatter\Formatter->getComponent()
#12 /var/www/html/forum/vendor/flarum/core/src/Forum/ForumServiceProvider.php(112): Flarum\Formatter\Formatter->getJs()
#13 [internal function]: Flarum\Forum\ForumServiceProvider->Flarum\Forum{closure}()
#14 /var/www/html/forum/vendor/flarum/core/src/Frontend/Compiler/Source/StringSource.php(38): call_user_func()
#15 /var/www/html/forum/vendor/flarum/core/src/Frontend/Compiler/Source/StringSource.php(49): Flarum\Frontend\Compiler\Source\StringSource->getContent()
#16 /var/www/html/forum/vendor/flarum/core/src/Frontend/Compiler/RevisionCompiler.php(174): Flarum\Frontend\Compiler\Source\StringSource->getCacheDifferentiator()
#17 /var/www/html/forum/vendor/flarum/core/src/Frontend/Compiler/RevisionCompiler.php(71): Flarum\Frontend\Compiler\RevisionCompiler->calculateRevision()
#18 /var/www/html/forum/vendor/flarum/core/src/Frontend/Compiler/RevisionCompiler.php(111): Flarum\Frontend\Compiler\RevisionCompiler->commit()
#19 /var/www/html/forum/vendor/flarum/core/src/Frontend/Content/Assets.php(118): Flarum\Frontend\Compiler\RevisionCompiler->getUrl()
#20 [internal function]: Flarum\Frontend\Content\Assets->Flarum\Frontend\Content{closure}()
#21 /var/www/html/forum/vendor/flarum/core/src/Frontend/Content/Assets.php(117): array_map()
#22 /var/www/html/forum/vendor/flarum/core/src/Frontend/Content/Assets.php(92): Flarum\Frontend\Content\Assets->getUrls()
#23 /var/www/html/forum/vendor/flarum/core/src/Frontend/Content/Assets.php(66): Flarum\Frontend\Content\Assets->addAssetsToDocument()
#24 /var/www/html/forum/vendor/flarum/core/src/Frontend/Frontend.php(62): Flarum\Frontend\Content\Assets->invoke()
#25 /var/www/html/forum/vendor/flarum/core/src/Frontend/Frontend.php(54): Flarum\Frontend\Frontend->populate()
#26 /var/www/html/forum/vendor/flarum/core/src/Frontend/Controller.php(32): Flarum\Frontend\Frontend->document()
#27 /var/www/html/forum/vendor/flarum/core/src/Http/RouteHandlerFactory.php(41): Flarum\Frontend\Controller->handle()
#28 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ExecuteRoute.php(27): Flarum\Http\RouteHandlerFactory->Flarum\Http{closure}()
#29 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ExecuteRoute->process()
#30 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ContentTypeOptionsHeader.php(21): Laminas\Stratigility\Next->handle()
#31 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ContentTypeOptionsHeader->process()
#32 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ReferrerPolicyHeader.php(30): Laminas\Stratigility\Next->handle()
#33 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ReferrerPolicyHeader->process()
#34 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/FlarumPromotionHeader.php(30): Laminas\Stratigility\Next->handle()
#35 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\FlarumPromotionHeader->process()
#36 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ShareErrorsFromSession.php(57): Laminas\Stratigility\Next->handle()
#37 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ShareErrorsFromSession->process()
#38 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/CheckCsrfToken.php(36): Laminas\Stratigility\Next->handle()
#39 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\CheckCsrfToken->process()
#40 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ResolveRoute.php(69): Laminas\Stratigility\Next->handle()
#41 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ResolveRoute->process()
#42 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/SetLocale.php(51): Laminas\Stratigility\Next->handle()
#43 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\SetLocale->process()
#44 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/AuthenticateWithSession.php(31): Laminas\Stratigility\Next->handle()
#45 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\AuthenticateWithSession->process()
#46 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/RememberFromCookie.php(52): Laminas\Stratigility\Next->handle()
#47 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\RememberFromCookie->process()
#48 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/StartSession.php(61): Laminas\Stratigility\Next->handle()
#49 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\StartSession->process()
#50 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/CollectGarbage.php(46): Laminas\Stratigility\Next->handle()
#51 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\CollectGarbage->process()
#52 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ParseJsonBody.php(28): Laminas\Stratigility\Next->handle()
#53 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ParseJsonBody->process()
#54 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/HandleErrors.php(57): Laminas\Stratigility\Next->handle()
#55 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\HandleErrors->process()
#56 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/InjectActorReference.php(25): Laminas\Stratigility\Next->handle()
#57 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\InjectActorReference->process()
#58 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(75): Laminas\Stratigility\Next->handle()
#59 /var/www/html/forum/vendor/middlewares/request-handler/src/RequestHandler.php(84): Laminas\Stratigility\MiddlewarePipe->process()
#60 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Middlewares\RequestHandler->process()
#61 /var/www/html/forum/vendor/middlewares/base-path-router/src/BasePathRouter.php(99): Laminas\Stratigility\Next->handle()
#62 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Middlewares\BasePathRouter->process()
#63 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Middleware/OriginalMessages.php(36): Laminas\Stratigility\Next->handle()
#64 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Laminas\Stratigility\Middleware\OriginalMessages->process()
#65 /var/www/html/forum/vendor/middlewares/base-path/src/BasePath.php(73): Laminas\Stratigility\Next->handle()
#66 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Middlewares\BasePath->process()
#67 /var/www/html/forum/vendor/flarum/core/src/Http/Middleware/ProcessIp.php(24): Laminas\Stratigility\Next->handle()
#68 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/Next.php(49): Flarum\Http\Middleware\ProcessIp->process()
#69 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(75): Laminas\Stratigility\Next->handle()
#70 /var/www/html/forum/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(64): Laminas\Stratigility\MiddlewarePipe->process()
#71 /var/www/html/forum/vendor/laminas/laminas-httphandlerrunner/src/RequestHandlerRunner.php(73): Laminas\Stratigility\MiddlewarePipe->handle()
#72 /var/www/html/forum/vendor/flarum/core/src/Http/Server.php(45): Laminas\HttpHandlerRunner\RequestHandlerRunner->run()
#73 /var/www/html/forum/index.php(26): Flarum\Http\Server->listen()

#74 {main}

Flarum core: 1.8.1
PHP version: 8.2.7
MySQL version: 10.6.12-MariaDB-0ubuntu0.22.04.1
Loaded extensions: Core, date, libxml, openssl, pcre, zlib, filter, hash, json, pcntl, random, Reflection, SPL, session, standard, sodium, mysqlnd, PDO, calendar, ctype, exif, FFI, fileinfo, ftp, gettext, iconv, mysqli, pdo_mysql, Phar, posix, readline, shmop, sockets, sysvmsg, sysvsem, sysvshm, tokenizer, Zend OPcache
+----------------------+---------+--------+
| Flarum Extensions | | |
+----------------------+---------+--------+
| ID | Version | Commit |
+----------------------+---------+--------+
| flarum-flags | v1.8.0 | |
| flarum-approval | v1.8.0 | |
| flarum-tags | v1.8.0 | |
| flarum-suspend | v1.8.0 | |
| flarum-subscriptions | v1.8.0 | |
| flarum-sticky | v1.8.0 | |
| flarum-statistics | v1.8.0 | |
| flarum-mentions | v1.8.2 | |
| flarum-markdown | v1.8.0 | |
| flarum-lock | v1.8.0 | |
| flarum-likes | v1.8.0 | |
| flarum-lang-english | v1.8.0 | |
| flarum-emoji | v1.8.0 | |
| flarum-bbcode | v1.8.0 | |
+----------------------+---------+--------+
Base URL: https://website.com/forum
Installation path: /var/www/website.com/html/forum
Queue driver: sync
Session driver: file
Mail driver: mail
Debug mode: off

luceos

flruser Flarum needs these php extensions:

curl, dom, fileinfo, gd, json, mbstring, openssl, pdo_mysql, tokenizer, zip

https://docs.flarum.org/install

It is very likely dom isn't installed. And even if it's installed/enabled for the php version running in cli (terminal, ssh), it might not be so for the php version active for web (fpm, apache etc).

flruser

Thank you, that was it!