Just about everything in this latest update doesn't work properly, takes longer to work and/or has lost functionality options. I was about to start donating because the app has been brilliant, but now there's no point. It needs to revert to it's pre-"update" version!
NOTE: I found Version history here: https://addons.mozilla.org/en-US/firefox/addon/nimbus-screenshot/versions/
I have re-installed 9.1.1