Crash-reports from Google Play

I get a lot of error reports in Google Play:

I think this comes from SDKBOX Play when an achievement is unlocked or something, but I’m not able to reproduce this.

I unlock an achievement with this code:

Is there a reason why this could cause errors? Is it because the user isn’t signed in or similar?

If you’re using sdkbox, plz, be sure to categorize correctly the topic.
@slackmoehrle i’m helping you. Hahaha.
@SteinOveHelset maybe you could paste the complete log of the error.

Oh, sorry about that!
I think I solved this. Seems like this error was throwed if the user was not signed in. Guess I didn’t test enough before publishing.

I thought maybe the SDKBOX plugin handled this automatically for me.

sorry, but SDKBox has not handled this.
you need to judge issignedin before unlock or submit score by yourself.
or SDKBox show a alert when a user try to unlock / submit without sign-in. is it ok?