The issue
When I modify the database according to this step, then flarum cannot display the content:
Flarum information
Flarum core 1.3.0
PHP version: 7.4.21
MySQL version: 5.5.5-10.4.19-MariaDB-log
Loaded extensions: Core, date, libxml, openssl, pcre, sqlite3, zlib, bcmath, ctype, curl, dom, fileinfo, filter, ftp, gd, gettext, hash, iconv, intl, json, mbstring, SPL, session, pcntl, standard, PDO, mysqlnd, pdo_sqlite, Phar, posix, Reflection, pdo_mysql, shmop, SimpleXML, soap, sockets, mysqli, sysvsem, tokenizer, xml, xmlreader, xmlrpc, xmlwriter, xsl, zip, exif, imagick
+--------------------------------+-------------+--------+
| Flarum Extensions | | |
+--------------------------------+-------------+--------+
| ID | Version | Commit |
+--------------------------------+-------------+--------+
| flarum-flags | v1.3.0 | |
| flarum-tags | v1.3.0 | |
| flarum-suspend | v1.3.0 | |
| fof-oauth | 1.2.2 | |
| flarum-approval | v1.3.0 | |
| flarum-markdown | v1.3.0 | |
| flarum-likes | v1.3.0 | |
| zequeen-acgembed-remastered | v1.1.2 | |
| v17development-seo | v1.8.0 | |
| the-turk-flamoji | 1.0.3 | |
| nearata-twofactor | v2.0.1 | |
| lazyeo-hljs | v2.0.1 | |
| justoverclock-og-meta-tag | 0.1.0 | |
| itnt-uitab | v0.4.2 | |
| ianm-synopsis | 1.2.0 | |
| ianm-level-ranks | 1.0.0 | |
| fof-user-directory | 1.2.3 | |
| fof-user-bio | 1.1.0 | |
| fof-upload | 1.2.3 | |
| fof-terms | 1.1.2 | |
| fof-socialprofile | 1.1.2 | |
| fof-sitemap | 1.0.3 | |
| fof-share-social | 1.0.1 | |
| fof-recaptcha | 1.1.0 | |
| fof-profile-image-crop | 1.0.1 | |
| fof-polls | 1.1.0 | |
| fof-pages | 1.0.4 | |
| fof-nightmode | 1.2.2 | |
| fof-links | 1.0.3 | |
| fof-html-errors | 1.1.0 | |
| fof-formatting | 1.0.2 | |
| fof-filter | 1.0.2 | |
| fof-drafts | 1.1.2 | |
| fof-doorman | 1.1.1 | |
| fof-cookie-consent | 1.0.2 | |
| fof-best-answer | 1.2.1 | |
| flarum-subscriptions | v1.3.0 | |
| flarum-sticky | v1.3.0 | |
| flarum-statistics | v1.3.0 | |
| flarum-nicknames | v1.3.1 | |
| flarum-mentions | v1.3.0 | |
| flarum-lock | v1.3.0 | |
| flarum-lang-english | v1.2.0 | |
| flarum-lang-chinese-simplified | v1.1.1.1220 | |
| flarum-emoji | v1.3.0 | |
| flarum-bbcode | v1.3.0 | |
| ffans-clipboardjs | v1.0.0 | |
| extiverse-mercury | 0.2.0 | |
| darkle-fancybox | 1.1.1 | |
| askvortsov-checklist | v1.3.1 | |
| antoinefr-money | v1.1.0 | |
+--------------------------------+-------------+--------+`
> [2022-06-15 00:10:11] flarum.ERROR: TypeError: Argument 3 passed to FoF\Upload\Formatter\TextPreview\FormatTextPreview::__invoke() must be of the type string, null given, called in (my domain)/vendor/flarum/core/src/Foundation/ContainerUtil.php on line 30 and defined in (my domain)/vendor/fof/upload/src/Formatter/TextPreview/FormatTextPreview.php:54
Stack trace:
#0 (my domain)/vendor/flarum/core/src/Foundation/ContainerUtil.php(30): FoF\Upload\Formatter\TextPreview\FormatTextPreview->__invoke()
#1 (my domain)/vendor/flarum/core/src/Formatter/Formatter.php(110): Flarum\Foundation\ContainerUtil::Flarum\Foundation\{closure}()
#2 (my domain)/vendor/flarum/core/src/Post/CommentPost.php(172): Flarum\Formatter\Formatter->render()
#3 (my domain)/vendor/v17development/flarum-seo/src/Managers/QADiscussion.php(116): Flarum\Post\CommentPost->formatContent()
#4 (my domain)/vendor/v17development/flarum-seo/src/Managers/QADiscussion.php(80): V17Development\FlarumSeo\Managers\QADiscussion->createTags()
#5 (my domain)/vendor/v17development/flarum-seo/src/Listeners/PageListener.php(147): V17Development\FlarumSeo\Managers\QADiscussion->handle()
#6 (my domain)/vendor/v17development/flarum-seo/src/Listeners/PageListener.php(107): V17Development\FlarumSeo\Listeners\PageListener->determine()
#7 (my domain)/vendor/flarum/core/src/Foundation/ContainerUtil.php(30): V17Development\FlarumSeo\Listeners\PageListener->__invoke()
#8 (my domain)/vendor/flarum/core/src/Frontend/Frontend.php(62): Flarum\Foundation\ContainerUtil::Flarum\Foundation\{closure}()
#9 (my domain)/vendor/flarum/core/src/Frontend/Frontend.php(54): Flarum\Frontend\Frontend->populate()
#10 (my domain)/vendor/flarum/core/src/Frontend/Controller.php(32): Flarum\Frontend\Frontend->document()
#11 (my domain)/vendor/flarum/core/src/Http/RouteHandlerFactory.php(41): Flarum\Frontend\Controller->handle()
#12 (my domain)/vendor/flarum/core/src/Http/Middleware/ExecuteRoute.php(27): Flarum\Http\RouteHandlerFactory->Flarum\Http\{closure}()
#13 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ExecuteRoute->process()
#14 (my domain)/vendor/fof/terms/src/Middlewares/RegisterMiddleware.php(59): Laminas\Stratigility\Next->handle()
#15 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): FoF\Terms\Middlewares\RegisterMiddleware->process()
#16 (my domain)/vendor/fof/oauth/src/Middleware/ErrorHandler.php(50): Laminas\Stratigility\Next->handle()
#17 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): FoF\OAuth\Middleware\ErrorHandler->process()
#18 (my domain)/vendor/flarum/core/src/Http/Middleware/ContentTypeOptionsHeader.php(21): Laminas\Stratigility\Next->handle()
#19 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ContentTypeOptionsHeader->process()
#20 (my domain)/vendor/flarum/core/src/Http/Middleware/ReferrerPolicyHeader.php(30): Laminas\Stratigility\Next->handle()
#21 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ReferrerPolicyHeader->process()
#22 (my domain)/vendor/flarum/core/src/Http/Middleware/FlarumPromotionHeader.php(30): Laminas\Stratigility\Next->handle()
#23 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\FlarumPromotionHeader->process()
#24 (my domain)/vendor/flarum/core/src/Http/Middleware/ShareErrorsFromSession.php(57): Laminas\Stratigility\Next->handle()
#25 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ShareErrorsFromSession->process()
#26 (my domain)/vendor/flarum/core/src/Http/Middleware/CheckCsrfToken.php(36): Laminas\Stratigility\Next->handle()
#27 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\CheckCsrfToken->process()
#28 (my domain)/vendor/flarum/core/src/Http/Middleware/ResolveRoute.php(67): Laminas\Stratigility\Next->handle()
#29 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ResolveRoute->process()
#30 (my domain)/vendor/flarum/core/src/Http/Middleware/SetLocale.php(51): Laminas\Stratigility\Next->handle()
#31 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\SetLocale->process()
#32 (my domain)/vendor/flarum/core/src/Http/Middleware/AuthenticateWithSession.php(31): Laminas\Stratigility\Next->handle()
#33 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\AuthenticateWithSession->process()
#34 (my domain)/vendor/flarum/core/src/Http/Middleware/RememberFromCookie.php(52): Laminas\Stratigility\Next->handle()
#35 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\RememberFromCookie->process()
#36 (my domain)/vendor/flarum/core/src/Http/Middleware/StartSession.php(61): Laminas\Stratigility\Next->handle()
#37 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\StartSession->process()
#38 (my domain)/vendor/flarum/core/src/Http/Middleware/CollectGarbage.php(46): Laminas\Stratigility\Next->handle()
#39 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\CollectGarbage->process()
#40 (my domain)/vendor/flarum/core/src/Http/Middleware/ParseJsonBody.php(28): Laminas\Stratigility\Next->handle()
#41 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ParseJsonBody->process()
#42 (my domain)/vendor/flarum/core/src/Http/Middleware/HandleErrors.php(57): Laminas\Stratigility\Next->handle()
#43 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\HandleErrors->process()
#44 (my domain)/vendor/flarum/core/src/Http/Middleware/InjectActorReference.php(25): Laminas\Stratigility\Next->handle()
#45 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\InjectActorReference->process()
#46 (my domain)/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(76): Laminas\Stratigility\Next->handle()
#47 (my domain)/vendor/middlewares/request-handler/src/RequestHandler.php(84): Laminas\Stratigility\MiddlewarePipe->process()
#48 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Middlewares\RequestHandler->process()
#49 (my domain)/vendor/middlewares/base-path-router/src/BasePathRouter.php(101): Laminas\Stratigility\Next->handle()
#50 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Middlewares\BasePathRouter->process()
#51 (my domain)/vendor/laminas/laminas-stratigility/src/Middleware/OriginalMessages.php(36): Laminas\Stratigility\Next->handle()
#52 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Laminas\Stratigility\Middleware\OriginalMessages->process()
#53 (my domain)/vendor/middlewares/base-path/src/BasePath.php(73): Laminas\Stratigility\Next->handle()
#54 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Middlewares\BasePath->process()
#55 (my domain)/vendor/flarum/core/src/Http/Middleware/ProcessIp.php(24): Laminas\Stratigility\Next->handle()
#56 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ProcessIp->process()
#57 (my domain)/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(76): Laminas\Stratigility\Next->handle()
#58 (my domain)/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(65): Laminas\Stratigility\MiddlewarePipe->process()
#59 (my domain)/vendor/laminas/laminas-httphandlerrunner/src/RequestHandlerRunner.php(96): Laminas\Stratigility\MiddlewarePipe->handle()
#60 (my domain)/vendor/flarum/core/src/Http/Server.php(44): Laminas\HttpHandlerRunner\RequestHandlerRunner->run()
#61 (my domain)/index.php(26): Flarum\Http\Server->listen()
#62 {main}
[2022-06-15 00:29:22] flarum.ERROR: TypeError: Argument 3 passed to FoF\Upload\Formatter\TextPreview\FormatTextPreview::__invoke() must be of the type string, null given, called in (my domain)/vendor/flarum/core/src/Foundation/ContainerUtil.php on line 30 and defined in (my domain)/vendor/fof/upload/src/Formatter/TextPreview/FormatTextPreview.php:54
Stack trace:
#0 (my domain)/vendor/flarum/core/src/Foundation/ContainerUtil.php(30): FoF\Upload\Formatter\TextPreview\FormatTextPreview->__invoke()
#1 (my domain)/vendor/flarum/core/src/Formatter/Formatter.php(110): Flarum\Foundation\ContainerUtil::Flarum\Foundation\{closure}()
#2 (my domain)/vendor/flarum/core/src/Post/CommentPost.php(172): Flarum\Formatter\Formatter->render()
#3 (my domain)/vendor/v17development/flarum-seo/src/Managers/QADiscussion.php(116): Flarum\Post\CommentPost->formatContent()
#4 (my domain)/vendor/v17development/flarum-seo/src/Managers/QADiscussion.php(80): V17Development\FlarumSeo\Managers\QADiscussion->createTags()
#5 (my domain)/vendor/v17development/flarum-seo/src/Listeners/PageListener.php(147): V17Development\FlarumSeo\Managers\QADiscussion->handle()
#6 (my domain)/vendor/v17development/flarum-seo/src/Listeners/PageListener.php(107): V17Development\FlarumSeo\Listeners\PageListener->determine()
#7 (my domain)/vendor/flarum/core/src/Foundation/ContainerUtil.php(30): V17Development\FlarumSeo\Listeners\PageListener->__invoke()
#8 (my domain)/vendor/flarum/core/src/Frontend/Frontend.php(62): Flarum\Foundation\ContainerUtil::Flarum\Foundation\{closure}()
#9 (my domain)/vendor/flarum/core/src/Frontend/Frontend.php(54): Flarum\Frontend\Frontend->populate()
#10 (my domain)/vendor/flarum/core/src/Frontend/Controller.php(32): Flarum\Frontend\Frontend->document()
#11 (my domain)/vendor/flarum/core/src/Http/RouteHandlerFactory.php(41): Flarum\Frontend\Controller->handle()
#12 (my domain)/vendor/flarum/core/src/Http/Middleware/ExecuteRoute.php(27): Flarum\Http\RouteHandlerFactory->Flarum\Http\{closure}()
#13 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ExecuteRoute->process()
#14 (my domain)/vendor/fof/terms/src/Middlewares/RegisterMiddleware.php(59): Laminas\Stratigility\Next->handle()
#15 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): FoF\Terms\Middlewares\RegisterMiddleware->process()
#16 (my domain)/vendor/fof/oauth/src/Middleware/ErrorHandler.php(50): Laminas\Stratigility\Next->handle()
#17 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): FoF\OAuth\Middleware\ErrorHandler->process()
#18 (my domain)/vendor/flarum/core/src/Http/Middleware/ContentTypeOptionsHeader.php(21): Laminas\Stratigility\Next->handle()
#19 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ContentTypeOptionsHeader->process()
#20 (my domain)/vendor/flarum/core/src/Http/Middleware/ReferrerPolicyHeader.php(30): Laminas\Stratigility\Next->handle()
#21 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ReferrerPolicyHeader->process()
#22 (my domain)/vendor/flarum/core/src/Http/Middleware/FlarumPromotionHeader.php(30): Laminas\Stratigility\Next->handle()
#23 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\FlarumPromotionHeader->process()
#24 (my domain)/vendor/flarum/core/src/Http/Middleware/ShareErrorsFromSession.php(57): Laminas\Stratigility\Next->handle()
#25 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ShareErrorsFromSession->process()
#26 (my domain)/vendor/flarum/core/src/Http/Middleware/CheckCsrfToken.php(36): Laminas\Stratigility\Next->handle()
#27 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\CheckCsrfToken->process()
#28 (my domain)/vendor/flarum/core/src/Http/Middleware/ResolveRoute.php(67): Laminas\Stratigility\Next->handle()
#29 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ResolveRoute->process()
#30 (my domain)/vendor/flarum/core/src/Http/Middleware/SetLocale.php(51): Laminas\Stratigility\Next->handle()
#31 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\SetLocale->process()
#32 (my domain)/vendor/flarum/core/src/Http/Middleware/AuthenticateWithSession.php(31): Laminas\Stratigility\Next->handle()
#33 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\AuthenticateWithSession->process()
#34 (my domain)/vendor/flarum/core/src/Http/Middleware/RememberFromCookie.php(52): Laminas\Stratigility\Next->handle()
#35 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\RememberFromCookie->process()
#36 (my domain)/vendor/flarum/core/src/Http/Middleware/StartSession.php(61): Laminas\Stratigility\Next->handle()
#37 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\StartSession->process()
#38 (my domain)/vendor/flarum/core/src/Http/Middleware/CollectGarbage.php(46): Laminas\Stratigility\Next->handle()
#39 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\CollectGarbage->process()
#40 (my domain)/vendor/flarum/core/src/Http/Middleware/ParseJsonBody.php(28): Laminas\Stratigility\Next->handle()
#41 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ParseJsonBody->process()
#42 (my domain)/vendor/flarum/core/src/Http/Middleware/HandleErrors.php(57): Laminas\Stratigility\Next->handle()
#43 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\HandleErrors->process()
#44 (my domain)/vendor/flarum/core/src/Http/Middleware/InjectActorReference.php(25): Laminas\Stratigility\Next->handle()
#45 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\InjectActorReference->process()
#46 (my domain)/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(76): Laminas\Stratigility\Next->handle()
#47 (my domain)/vendor/middlewares/request-handler/src/RequestHandler.php(84): Laminas\Stratigility\MiddlewarePipe->process()
#48 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Middlewares\RequestHandler->process()
#49 (my domain)/vendor/middlewares/base-path-router/src/BasePathRouter.php(101): Laminas\Stratigility\Next->handle()
#50 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Middlewares\BasePathRouter->process()
#51 (my domain)/vendor/laminas/laminas-stratigility/src/Middleware/OriginalMessages.php(36): Laminas\Stratigility\Next->handle()
#52 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Laminas\Stratigility\Middleware\OriginalMessages->process()
#53 (my domain)/vendor/middlewares/base-path/src/BasePath.php(73): Laminas\Stratigility\Next->handle()
#54 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Middlewares\BasePath->process()
#55 (my domain)/vendor/flarum/core/src/Http/Middleware/ProcessIp.php(24): Laminas\Stratigility\Next->handle()
#56 (my domain)/vendor/laminas/laminas-stratigility/src/Next.php(51): Flarum\Http\Middleware\ProcessIp->process()
#57 (my domain)/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(76): Laminas\Stratigility\Next->handle()
#58 (my domain)/vendor/laminas/laminas-stratigility/src/MiddlewarePipe.php(65): Laminas\Stratigility\MiddlewarePipe->process()
#59 (my domain)/vendor/laminas/laminas-httphandlerrunner/src/RequestHandlerRunner.php(96): Laminas\Stratigility\MiddlewarePipe->handle()
#60 (my domain)/vendor/flarum/core/src/Http/Server.php(44): Laminas\HttpHandlerRunner\RequestHandlerRunner->run()
#61 (my domain)/index.php(26): Flarum\Http\Server->listen()
#62 {main}