I got an exception while using the Image Editor of Greenshot.
Steps taken before the screenshot:
took a "region" screenshot
added a rectangle (with drop shadow)
added an ellipse (with drop shadow)
let that window sit for several minutes during an interruption
took another "region" screenshot (opening a 2nd image editor window)
quit the 2nd image editor window
back in the 1st image editor window, selected the ellipse
clicked icon for drop shadow to turn it off
EXCEPTION THROWN HERE
copied modal window with exception text
clicked icon for "copy image to clipboard"
pasted into Outlook email just fine