After I updated today my Nexus 4 from Android 5.0 to Android 5.1 sync is not working and all my contacts don't appear on device. It's always "Contact list is being updated" message and endlessly running sync of Contacts. All other applications synced successfully.
I have all my contacts on my Google account but Nexus 4 is in trouble and I can't use it.
What can I do to fix a problem?
Have you tried restarting again also if that doesn't fix things try clearing cache.
Wipe cache partition
If the phone is not working correctly, you may need to master reset it and also clear the cache partition. These two resets clear different parts of the phone storage. Unlike a master reset, wiping the cache partition does not delete your personal data.
To wipe the cache partition, follow these steps:
Back up all necessary data that is on the internal memory.
Turn off the device.
Press and hold the Volume Up and the Volume Down and Power keys at the same time for about 10 seconds.
An image of an Android lying on its back will appear.
Press the Volume Down key twice until "Recovery mode" appears on the screen.
Press the Power key to restart in "Recovery mode."
An image of an Android with a red triangle will appear.
While holding down the Power key, tap the Volume Up key.
The Android System Recovery screen will appear. Release all keys.
Use the Volume keys to scroll to wipe data cache partition and press the Power key to select.
The phone will restart.