On a Samsung Galaxy Tab SM-T320 I was getting the following message after upgrading CyanogenMod to the latest stable 12.1 build:
Unfortunately, Google Play services has stopped.
This message would occur constantly, maybe every 3 seconds or so.
On pressing the “Report” button I would see a preview of a Crash Report that stated:
[CRASH] com.google.android.gms threw android.database.sqlite.SQLiteException
android.database.sqlite.SQLiteException: Can’t downgrade database from version 65 to 64
So I used adb to shell into the device from my laptop and became the root user (using the su command).
Essentially I just had to delete any databases that were being used by Google Play Services. This was a lot. To find out which I would run the command:
logcat |grep -B 3 -A 20 downgrade |less
and look for lines that stated:
E/DatabaseUtils( 1180): at com.android.providers.telephony.SmsProvider.
and so forth and then run
I think these were the main two database directories I had to erase. You will probably want to back up any SMSs you have (although this doesn’t apply in the case of a tablet with just wifi).
I also had a similar crash with the clock and had to erase its databases, too.
Then reboot. Should be no more errors.