Android app crashing when it wasn't running

Question

Sometimes my Android app crashes randomly, when it was not previously open. I get a message that says, "Unfortunately, <app> has closed." However, it was already closed, usually for a significant period of time before this crash occurs. I use a crash reporting service but these crashes are not reported, so I have no clue what's going on.

I have seen this happening to other apps (that were not my own) in the past, so I thought this would be an issue I could easily google, but I can only find results related to crashes while the app IS running.

Any ideas as to why this might happen or resources to point me in the right direction would be much appreciated :)

EDIT: I am not asking anyone to fix this crash or determine WHY it's crashing. I know very well how impossible that is without any logs. I am just asking what, in theory, might cause an app to crash while it was not running.

Answer 1

Its difficult to say why it might be happening without a log, but a way to find it would be to use android monitor on android studio and see any kind of suspicious logs which could indicate why this might be happening. Also you need to be familiar with android debugging tools in order to debug this. A more general reason could be a system background service that might be running and waiting for results. Some pointers to check :

1. If using GCM, check if implementation doesnt cause any unchecked
   exception.
2. If using receivers in manifest, check none causes any unchecked exception.
3. If using alarmmanager in any way, check for any unchecked exceptions.
4. If using application level methods detecting
   app closure such as onTrimMemory or onTerminate, check any unchecked exceptions.