"Cannot open clipboard" when moving items in Microsoft Excel

[sgturner]

I have a tree open in TreeDraw (imported from GEDCOM but not yet saved) and I am also working in Excel (365). Whenever I drag and drop the contents of a cell in Microsoft Excel, TreeDraw gives me a 'Cannot open clipboard' error window behind the current window. Also happens if I copy a cell into the clipboard, but not when I paste it and not if I copy the contents of a cell.
When I go back to TreeDraw I have to delete all these windows before I can navigate around my tree.

A previous topic to this suggested that it was related to AutoSave in Excel, but that is turned off (in the Options) and it only happens when I do the above inside Excel.

Regards
Sue