Hi
Close your app
Then
1. Go to the Apps Page on Power Apps .Com
2. Find your app
3. Click the ... on its row
4. Select Details => Monitor
5. When Monitor Opens
6. Click Play Published App
7. Go to the now opened App Tab
8. Cause the error
9. Switch to the Monitor Tab
10. In the Filter (top right) type Error
11. Find the group of errors 2-4 that will be talking about the error you had (there could be loads of errors you dont even know about, but you want to find the group related to your error)
12. The specific row you want will have 4 Tabs, that are part of the Right Side Fly out window when you click/double click the row
13. Select the Response Tab (#4)
14. Expand Header and Body
Body should tell you exactly whats wrong
Fix it.
You are done.
please mark this as the answer if this helped you.