It seems that after updating my app to use compileSdkVersion 23 from 21, some users have started to complain that they are unable to install the app from the app store referencing error code 505.
I have looked at other people with install issues with error code 505 and a lot point to permission package name conflicts which arose with lollipop phones, but this would not explain why this problem only started to happen after updating my compileSdkVersion. I also looked through my manifest and the only permission using a package name other than "android.permission" were:
<uses-permission android:name="[my package].permission.C2D_MESSAGE" />
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
which both seem correct. Has anyone else seen this issue?