Keynote shortcut to Align Objects not working.

It seems to work for me.

Do you see the keyboard combination in the menu bar? that's the first check that the Keyboard Shortcut is setup (e.g. it can 'find' the relevant menu item to apply):

Additionally, you say you setup '... Keynote -> Align Objects Center -> Control-Shift-C'... did you include 'Align Objects Center' in the Keyboard Shortcut setup? if so, that could be your problem. You need to specify the exact menu item... its hierarchy in the menu bar doesn't matter, so in this case it should just say 'Center':

Glad I could help.

It doesn't seem unreasonable to include the hierarchical menu in the Keyboard Shortcut settings, and I know I did that when I first tried using this.

Also makes me wonder what would happen if multiple hierarchical menus have the same wording - without specifying the parent menu, there's no way to control which one the keystroke is applied to. I'll have to find an app that meets this criteria and see what happens.