Warning: Undefined array key 1

Drupal 9 is no longer maintained. Can this be reproduced on a supported release?

As already noted, Drupal 9 is no longer supported. If this issue can be reproduced in Drupal 10 or 11. If more information is not provided within the next three months, this issue will be closed.

I faced the same problem using Drupal 10.3. I Used exposed filter widget "radio buttons/checkboxes". And if I didn`t select all the buttons, I got an error Warning: Undefined array key 1 in Drupal\content_moderation\Plugin\views\filter\ModerationStateFilter->opSimple() and AJAX didn`t work.

So, I installed the patch → and everything works correctly.

Thanks

This patch worked for me! Thanks!