App crashes when installed but not in live companion testing?

[Taifun]

Probably because you are switching screens not correctly or because of using too large images. .
See tip 1 and 2 here

General Tips and Tricks for App Inventor/Kodular

Use different screens wisely Before starting to create another screen, first you should think about is it really necessary? See also Building apps with many screens and SteveJG’s post about advantages/disadvantages, because in only one screen you also can use vertical arrangements to simulate different screens, just set the arrangements to visible = true/false as needed… If you decided to use different screens, then you should switch them correctly, else you will run out of memory after a wh…

Taifun