Account Hacked Blizzard or game account hacked or compromised.
The problem has since been resolved, however you may have some corrupt files preventing the latest update from downloading and installing.
I would go ahead and follow the instructions here and that should hopefully get you fixed up.
Of course, do not remove security software if you can't reinstall it, and always restore disabled security after testing.
Heavy Soldier, It sounds like something is preventing the launcher from installing the game files. Disabling or temporarily uninstalling firewall and anti-virus programs (Norton, Mc Afee, etc) can permit the launcher to run successfully.
In a last act of desperation before borrowing the DVD from a friend to try and load it that way, I had some Raymond Chen style psychic insight and thought it might be a multithreading bug.
Every single time, over and over and over and over again.
It also works for the "Updating files..." progress bar error. page=1 TL; DR noob friendly version: This worked for me, I was finally able to log in after 1.5 days of failed attempts. Go to WTF/Find and edit SET gx Api "D3D11" to SET gx Api "D3D9" Start Launcher.
Update - Possible fix for 15544 Update Okay, so I couldn't log in after the 15544 Update. If the progress bar is stuck, try it a few more times.
I've tried many of the remedies mentioned in past posts regarding this subject, such as restarting, logging out and exiting the program....