File Display toolbar greyed out in Customize

I have been trying to figure out the following:
Customize Toolbars...
"File Display" is grayed out.


That's just indicating that you cannot turn that toolbar on and off there, as it's been assigned as the File Display Toolbar, which is special since it appears above each file display (i.e. twice if a window has two file displays open at once).

You can change which toolbar(s) is used in the special File Display Toolbar position via Preferences / File Displays / Border.

Thanks Leo... just what I was after.