Diablo launcher stuck at updating tools
Opening Diablo 3 Problem
Rest assured, you weren't alone as I was a victim of frozen update screens not wanting to download as well.
I even took a picture with my cell and sent it to my fellow GameSkinny team members and they couldn't figure it out.
After that, the download speed vastly improved and, which is more important, the initializing screen halt was gone.
Under the General tab, select the Selective startup.
Fix Battle.net update issues
After nearing 10 hours of frustration, I was ready to do some remodeling on my walls with my head and fists--that's when my phone rang.
I've already heard a few people say they need to restart the launcher several times before it does anything.
This replaces the launcher for all Blizzard games, and works similar to the older launchers, with background updates, repair tool, and more.
These can slow down downloads and even prevent the client updates.