I checked your trouble with widget, when i download widget directly from app store i have same error no matter what i do. When looking for fix i tried something different, so i downloaded widget directly from github files, and suddenly error no longer occur, but widget seems dont working. Breakpoint on microflows never trigger. Test project located on github work like a charm with widget, but is mendix version 7.15.1. So in my opinion this widget is no longer supported, and without some serious changes in code we can’t use this in newer version of modeler.
Do anyone have any other methods to achieve the same functionality?
I can’t believe this functionality isn’t a core Mendix feature!?!?!?