App keeps closing when I open it

Have been making some changes to the project, adding lines and changing trap names and now when me and my work mate try to open our apps on our phones app wont stay open, it opens for a second and then closes, I changed permission of works app so he can only see assigned lines and the app is now working for him but I need us both to be able to see everything, any suggestions as to why its doing this and what we can do to fix it?
Up is up to date, have deleted and then reinstalled along with restarting phones.

@toby Can you please send me through the details of the project to