Invalid argument supplied for foreach() in Drupal\Core\Field\FormatterPluginManager

Still on D9.5.2:

Message	Warning : foreach() argument must be of type array|object, null given dans Drupal\Core\Field\FormatterPluginManager->getOptions() (/home/xxx/www/xxx/sited9/web/core/lib/Drupal/Core/Field/FormatterPluginManager.php ligne 176)
#0 /home/xxx/www/xxx/sited9/web/core/includes/bootstrap.inc(347): _drupal_error_handler_real(2, 'foreach() argum...', '/home/provence-...', 176)
#1 /home/xxx/www/xxx/sited9/web/core/lib/Drupal/Core/Field/FormatterPluginManager.php(176): _drupal_error_handler(2, 'foreach() argum...', '/home/provence-...', 176)
#2 /home/xxx/www/xxxx/sited9/web/core/modules/field_ui/src/Form/EntityDisplayFormBase.php(755): Drupal\Core\Field\FormatterPluginManager->getOptions('language')

I read over this issue carefully. It is a bug report, but the bug report lacks detailed steps to reproduce that community contributors can follow to solve the problem. This will not be solved without more information.

Hello.
What kind of infos do you need more ? I guess it could be related to my 500 errors as authentified user.

Another error:

The website encountered an unexpected error. Please try again later.
Error: Cannot use object of type Drupal\Core\Entity\Entity\EntityFormDisplay as array in Drupal\filefield_sources\Controller\ImceController->page() (line 45 of modules/contrib/filefield_sources/src/Controller/ImceController.php).
Drupal\filefield_sources\Controller\ImceController->page('node', 'fiche_bts', 'field_detail_fiche_bts', Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 580)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 169)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 81)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 182)
Drupal\cleantalk\EventSubscriber\BootSubscriber->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 713)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Steps to reproduce:
1- Migrate website to D8 or D9 from D6, with CCK managed fields
2- Edit the "admin/structure/types/manage/TYPE/form-display", and enable or disable field about language or metatag
3- Then go to edit a node of this type, and this lead to 500 error ( view mode for authentificated user) or error message

That stack trace points to an issue in module filefield_sources, not Drupal core.

It would be nice to have a stack trace for the error that this issue seems to be about. This is what I mean—this issue lacks focus.

Will see on filefield_sources side so.