I found a problem when updating my Xiaomi M-One Plus to 2.12.7 using Xiaomi recovery. System one was fine, but when I rebooted to system two to upgrade it repeatedly showed the message 'Unfortunately, the process com.android.phone' has stopped'. If I clicked Report MIUI it showed details of a RuntimeException. First part of exception was: java.lang.RuntimeException: Unable to get provider com.android.providers.telephony.SmsProvider: android.database.sqlite.SQLiteException: Can't downgrade database from version 71 to 70. I managed to resolve this by upgrading system one again using the Updater app (i.e. clear cache / wipe data etc and install 2.12.7 to system one in recovery, reboot to system one and use Updater app to install 2.12.7 again). For some reason this sorted out the FC in system two. Hope this helps anyone else who has this problem. I also posted this on the MIUI forum (http://en.miui.com/thread-1253-1-1.html) and someone said they also had the problem on the MI2.