At user/1/activitypub/settings I saw a warning message that:
> Warning: the private folder has not been configured.
but it still let me submit the form.
That then produced a ton of errors:
> Warning: is_dir(): Unable to find the wrapper "private" - did you forget to enable it when you configured PHP? in Drupal\Core\File\FileSystem->prepareDirectory() (line 502 of core/lib/Drupal/Core/File/FileSystem.php).
Disable the form submit button if the private folder is not available.
Active
1.0
User interface