Originally Posted by NNolan
Ok, I figured out what was wrong...it doesn't like a cut-and-paste from the Amazon "Manage Your Devices" web page. Removing the embedded spaces in the serial number from within the Configure tool doesn't work; I had to copy it to a text file, remove the spaces there and then copy it into the Configure section of the tool.
It's likely that you had a trailing space. The tools are fussy.