[TYPO3-english] Re: Typo 8.7.2 error saving content element forms

[Wim Spijker]

It happens when saving a form made in TYPO3 8.7.1. When saving, or when try to unhide that content element I get the error.
So I made a new form in TYPO3 8.7.2. then there are no errors, not by saving, nor by un-hide. 
I had 6 forms made in TYPO3 8.7.1 and all 6 had the same error. 
I think it has to do with forms made in TYPO3 8.7.1

I make new forms.