Ok guys, I have been plagued with the "Downloaded but could not open" error (8018830f) <<< I know that error code by heart now
I tried hard reset, I tried clearing temp, I tried rebooting and just about everything, nothing worked
Then I downgraded to WP8.0 Black using Nokias Recovery Tool, updated officially to 8.1 Cyan, then installed the Dev preview app and updated to 8.1 update 1, and it worked perfectly, now running 8.1.1 on my L625
So if any of you are in a hurry for the update, and don't mind wiping your phone (Do a backup first), that's the way to do it