I've noticed that, while looking around in the menus, there's a chance you'll hear the 'menu up' and 'menu down' sounds at the same time.

this can lead to a soft-lock if you exit the menu completely. the only way I know how to avoid a soft-lock is to exit the world and re-enter the world again.

otherwise, if you are in a soft-lock state, then your only option is alt + F4 to force the program to close.