Fatal Error due to class object inconsistencies in Form Wizard
Elements in the form wizard can either be defined by TypoScript or by using the accordant wizard. Some of these elements don't have a counterparts in the ExtJS form wizard and thus only work in the TypoScript mode. In these cases, the missing JSON conversion objects lead to fatal errors.
Example TypoScript for triggering the error:
8 = IMAGEBUTTON
label = Image button
src = /typo3conf/ext/bootstrap_package/Resources/Public/Images/Backend/TopBarLogofirstname.lastname@example.org
value = value