Excel opening ghost window.

[greg10e]

Excel keeps opening a second (ghost) window whenever I open a file.
If I close down the ghost window, it closes the real window as well. How do I get rid of the ghost window?

[#2]

Does this happen when you open a specific file or does it also happen when you just open excel (from the start menu, without opening a specific file but only excel itself)?

[#3]

Happens whenever I open any Excel file from Windows Explorer or taskbar shortcut. (This is my usual mode of working with Excel.)

Doesn't happen if I open Excel then select File>Open.

Only happens on my desktop, not on my Surface - running latest Insider Slow release on both. 19041.21

@PascalKTeam 

[#4]

That's odd. Have you tried to repair office? I can't think of anything that might cause the issue.