Microsoft is working hard to fix these issues.This error is fixed now for my L925, (on Lumia Cyan). But other problem come during update process.
The update gets downloaded and installed properly, but when phone is restarting to finalize the update (cog wheel screen), error message come that "Phone update can not be done" and there is an error code again.
I have already tried 3 times but same issue everytime.
Actually we should wait for little time, no need to get exited and waste our precious internet data.
Don't try hard or soft rest, don't try to recover through NSU.
Thanks.