It appears that you have physical access to the device in question? If not, you will need that.
What you need to do then is get a log and/or trace of the crash. You should run the app directly on the device via Android Studio with “fuse build -tandroid -d” command, and then selecting Run -> Debug in Android Studio. The debugger then should tell you what the cause of the crash was.
Once you do that, we might be able to suggest a solution.