Fix #2: Uninstall Roblox Player and delete the Appdata folder. If everything is updated but Roblox is still crashing, the next solution that you can try is to completely remove the game.

If Roblox keeps crashing or gets disconnected with error An unexpected error and Roblox needs to quit on Windows 11/10 PC, then here are the working fixes.

The “An unexpected error occurred” error message effectively prevents you from launching Roblox on your gaming platform. What causes Internal Server error 500 in Roblox?

If KRNL-Injector failed to find the Roblox process, delete KRNL App data and see. If that doesn't help follow the solutions mentioned in this post to resolve the issue.