I’ve been having the same issues. Diablo 3 works fine, but Diablo 4 won’t launch. The button will say “launching”, “play”, or “update” to initialize an update that does nothing and won’t tell you if it’s failed. I’ve checked for updates for the game, the battlenet launcher, my pc and drivers. I’ve run the registry cleaner, defragmented the drive, run disk cleanup, checked my ISP, router, and still nothing changes. It’s genuinely starting to feel like there’s nothing else I can do. Maybe the updates aren’t supported in windows 10?