Snipping tool won't save - possible solution

I've used the Windows "snipping tool" for years - it lets you grab a snapshot of part of the screen and then paste it or save it to a file. Great for grabbing copies of error messages to show to support people.

Just recently, I found I could capture the screen OK but when I hit the Save button or File->Save As, nothing happened. I Googled, found a few solutions but none of them worked. Then I found this somewhat complicated thread which gave me a clue.

The bottom line is that you get this problem if Windows can't access your "Pictures" library - even if you had no intention of saving to that library.

Try right clicking on Pictures in Windows Explorer and choose Properties - here's what I saw

My F drive is a portable drive and I'd disconnected it. Plugging it back in fixed it.