Xcode keybinding greyed out, impossible to delete or modify.

Reassigning a binding (Opt Maj Enter) for a macro I created a conflict. When I went to resolve it I found that the original keybinding was grayed out, and that it was impossible to reassign the key , or delete the entry.

It is quite possible an xlm file somewhere with a problem. Any idea on how to remediate it?

Xcode keybinding greyed out, impossible to delete or modify.
 
 
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