Game crashes on push notification (Android)

So I'm trying to get push notifications to work on a game, but whenever it (should) receive a push notification the game crashes, "Unfortunately, game has stopped.". I still get the push notifications, but only when the phone is not locked. Also the game crashes without it even being running.

For GCM I'm using Unity-GCM plugin and push notifications are send from Gamespark. So I got couple of questions that might help me figure out what is wrong:

• In the project I have another plugin, Android Native, which also has GCM features. Could they be mixing things up causing it to not work?

• For push notifications Gamespark has 4 fields to send the info with, but Unity-GCM only seems to have 3. Could be formatting in the push JSON be causing crashing?

• In the Android manifest there is the app_id, but since the game is still in development it is not register in the Play store and doesn't have the id yet. Could missing/wrong id cause crashing?

Any help would be much appreciated.