I really like the shortcut key to bring up the help menu (Cmd + Shift + /). I use it navigate the menus by typing in short words.
However, I've just noticed that it's not currently working. Instead, I get an error noise whenever I press cmd+shift+/.

My first thoughts was that either another program is intercepting the shortcut in a global way. But I don't what that program might be.
- How can diagnose the cause of this shortcut key failure (Cmd+Shift+/)?
- How can I resolve the problem?
UPDATE:
- I tried changing the shortcut key in "keyboard shortcuts" to something else (e.g.,
Cmd + Alt + Shift + /). This alternate keyboard shortcut also triggers the error noise. So this suggests that the problem is not a conflict with another program.