Ok i can reproduce your issue as well. Seems to be a bug in Mendix.
If you use a decimal or integert over an associated entity you will get this error. If you use an string or enum attribute it show a dropdown and works fine.
So what you can do is:
- Create a support ticket with Mendix to tell them the issue: https://support.mendix.com/hc/en-us
- Fix it in your case with a listview instead of a datagrid, and style the listview as a datagrid
- Or fix it by creating an extra string attribute of the integer value
any updates on this? I am also receiving this error using Decimal, but I need to use Decimal
It was fixed in Studio Pro 9.10.0, 9.6.7 and 8.18.16.