Can't Assign Macro in Excel - Solved

I spent at least 30 minutes struggling with my new computer because the path name of my macros had changed. Turns out, you must manually change every item in your Excel palettes that calls a macro. That's easy, you control click on the palette icon, select 'assign macro', and choose the macro.

But although that command was not greyed-out, when I selected it, nothing would happen. There was no error message.

I found no solutions on the internet, and in the course of the 30 minutes, tried various desperate things involving new taskbars, searching for mysterious excel.xlb files, VBA scripts to build taskbars. In the course of that, I broke a bunch of things on the palette. But I found the solution, and joined this group, just so I could tell the world.

You have to have some worksheet open.

Yes, that's it. It makes no sense, but that's it.