Hi Jain,
we also have discovered the same issue.
We believe that Mendix 9 has deactivated the Entity.isPersistable. Widgets that use this function are not longer working with Mendix 9.
Is there someone out here who knows how to call that persistable check now?
The JS-Console does not help a lot...
i
Best Regards,
Frederik
I had exactly the same Problem. I used a Microflow to fill in my Data Source but I chose the option “Database” instead of “Microflow” which causes the exact same error, see the screenshot attached.
It seems that your usage of isPersistable does not match with something within the graph. Check the documentation to see if there is something missing.