Diablo 3 stuck at updating blizzard launcher
If you try running the Diablo III file and nothing appears to be happening, check to see if the Windows Service for Secondary Logon is enabled. This service being disabled may also cause the system to appear to hang during the "Updating Setup Files" portion when run.The game requires it and will not run if it's disabled. f you're encountering crashing when launching the game, we ask you to check and see if you have any of the following third party programs running.Most of these can be solved by commonsense troubleshooting techniques, but some others are a bit more .We'll keep this post updated throughout the next couple of days with the latest problems and info on how to fix them.Blizzard is an online gaming platform operated by Blizzard Entertainment.The service was previously known as and enables online game-play for games including World of Warcraft, Starcraft, Diablo, Hearthstone and Heroes of the Storm.
In fact, setting the tools to run in Compatibility Mode may cause other issues with the Blizzard Launcher.
Update: ATI has released a Catalyst 12.4a driver hotfix for the affected cards.
Please check this link for more information: the Beta, several startup issues were resolved by setting the Diablo III tools to run in Compatibility Mode.
I'd recommend restarting the downloader to see if you can pick that up.
When restarting the downloader, make sure to select the same download folder that you did before.This can often times be caused by closing the downloader early.