It seems as if many users on Windows 11 have been experiencing issues with launching the ROBLOX player, here’s the easy fix to it!
-Attempt to launch in administrator (Right click roblox player, then left click run as administrator and click yes)
-Attempt to launch multiple times
-Reinstall Roblox Player
-Restart Computer
If none of these ideas work, attempt to watch videos and try contacting usage support for more help on this issue!
EDIT: Use CTRL + ALT + DEL to view the task manager and stop the roblox player from running before running it again.