Hi There, getting "Object reference not set to an instance of an object." error while opening the form. As per server logs, the issue is happening because of a deleted data connection still trying to load while opening the form,, which seems to be a bug. After adding same data connection again, then issue not appearing but actually that data connection not needed. How to avoid the issue with out adding that data connection. Please find the attached server log files and error screen shot
This error is a very generic error so could be many reasons why user is getting error; Get the Evolve/Composer logs from the user and check if it is relating to the data connection that might be redundant or had been changed.
If user is having this issue with the Migrated solution then it could be The control was textbox, but initially (in foundation), it was a dropdown, therefore had range property with data connection reference.
Root cause: Changing the type of dropdown to textbox does not delete the range property from the schema of the dropdown. In Evolve a code piece assumes that any control that has range property is a dropdown, and therefore tries to fetch data from the data connection.
If so then perform below workaround
1) Change the textbox to dropdown, changed the range of dropdown to the static value, and again changed the type to the textbox.
2) Redeploy the solution and verify .
vi) Another way to resolve the issue can be, completely delete the control (from FormData too) and then re-add the textbox.