My App will no longer open in preview - Appgyver IOS App

Suddenly, today, my app will no longer preview on my device or in the Web Preview…on my device, the spinner is loaded after selecting the App never goes away and on the Web preview…it just shows “Loading”. I have tried to revert to a saved backup, but none of them will open in preview mode.

Any help appreciated, because I am stuck!

On further analysis, it appears that my flow logic was no longer hiding the spinner, thus causing the problem.