Keyboard Shortcut for "Show All"?

[Thunderbird]

I want to make a keyboard shortcut for "Show All" for the opposite shortcut of "Hide Others". There is only a click command in the Application menu for "Show All".

Here's what I did:

System Preferences > Keyboard > Keyboard Shortcuts > selected "Application Shortcuts" > highlighted "All Applications" > clicked "+" and then typed "Show All" in the menu title field, and entered "Option" + "Command" + "S" in the "Keyboard Shortcut:" field.

Nothing happened. Do I need to do anything else?

 

[GGJstudios]

That's probably because Command+S is already assigned in most applications as File > Save or File > Save As

 

[Thunderbird]

The keys were option + command + s. Are you saying even a part of another shortcut combination won't work?

I've tried option+command+U as well, and it didn't work either.