KVS synchronize with completion handler failed on ios 10.3 update

After updating iPhone 6 to iOS 10.3, I get error message "KVS synchronizeWithCompletionHandler failed" after entering Apple ID as prompted. This step can be skipped, but phone says iCloud services may not be set up completely.

Can anyone tell me how to fix this error?

thanks,

I didn't find the right solution from the internet.
References:
- https://discussions.apple.com/thread/7911329
- Product demo video Examples