Joomla! 4.3.4 Seblod 4.1.1 My form is an app from the 3 Series version Casiopeia Work local in WAMP PHP 8.0.26
I work in the menu with the category list. However, a category blog causes the same error. If I publish a post with my form, everything is fine. But if I create a second post using the same form, I get a boat trap error: 0 Joomla \ cms \ html \ Helpers \ boottrap :: start tabet (): return value must be of type string, none returned
In this forum it is corrected by the fact that Helix had something to do with it - but I don't use Helix.
What can I do?
The shape itself can be viewed in my old site:https://www.time4Joomla.de/ms-outlook/319-thtml
And are downloaded:https://www.time4mambo.de/download/seblod/app_cck_excel.zip