Hi,
Can you do the following steps please and it should tell you whats wrong.
If this happens in dev too it makes it easier, but let's do it based on the published one
Steps
1. Close the App if Open
2. Go the Power Apps home page, and click on Apps on the left navigation
3. Find your app
4. Click the ... on the save line as your app, Select Details => Monitor
5. once monitor loads, click Play Published App
it will starts your app
6. Go to the app tab
7. Make the error happen
8. switch back to the Monitor Tab
9. Filter top right, type Error
10. look through the errors.
One of them will a group of them related to your problem
You want to find the line, that specifically has 4 Tabs when the Fly out window appears on the right
11. Click the 4th (Response Tab)
12. Expand Header and body
One of them will hold the better error message, like insufficient privileges etc.
Bring it back here if you need help, otherwise it should tell you the issue and you can resolve it and you are good.
Please select this answer if it helps you
