10000548 
Message
Shortcut has been allocated
Diagnosis
You have chosen 
Tools 
My Shortcuts Customize 
to open the Customize window, and you have attempted to allocate a shortcut to a document.
However, the shortcut you have selected has already been allocated to another document.
Procedure
In the Customize window, do one of the following:
Select a shortcut that has not been allocated.
Delete the shortcut you want to re-allocate:
Select the window where the shortcut is allocated.
Choose Remove and then choose the OK button.