I edited the article class in ez backend and added and removed some attributes. Then I stored the class definition.

If I reload an article on my website now I alway get an error:

"Notice: Undefined offset: 481 in /var/vhosts/<mywebsite>/html/vendor/ezsystems/ezpublish-kernel/eZ/Publish/Core/Repository/ContentService.php line 1914"

After deleting the cache files of symfony everything works fine. I'm working on the DEV Environment.