Android : Can't locate error origin

I get this weird error in my MainActivity, can't reproduce it myself but this is what I get in Crash report:

java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=65538, result=0, data=null} to activity {lv.mobi.android/lv.mobi.android.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:3455)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3498)
at android.app.ActivityThread.access$1300(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1294)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:212)
at android.app.ActivityThread.main(ActivityThread.java:5135)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:877)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:693)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at lv.mobi.android.b.aj.a(Unknown Source)
at android.support.v4.app.FragmentActivity.onActivityResult(Unknown Source)
at lv.mobi.android.MainActivity.onActivityResult(Unknown Source)
at android.app.Activity.dispatchActivityResult(Activity.java:5423)
at android.app.ActivityThread.deliverResults(ActivityThread.java:3451)
        ... 11 more

I thought it could be something in onActivityResult, but can't figure out what, my result function doesn't have much in it:

    @Override
protected void onActivityResult(int _requestCode, int _resultCode, Intent _data) {
    super.onActivityResult(_requestCode, _resultCode, _data);
    if(_resultCode==Activity.RESULT_OK){
        reloadUser();
    }
}