Error updating Exclusions for existing Nonstop Backup

I have a Nonstop Backup that has been running successfully for about a month. I opened the File Exclusion dialog, added a directory "C:\Program Files (x86)\Automated QA\", clicked OK, and the Nonstop Backup screen showed the error message "There is not enough free space" (see the error.png attachment). The attached log file was also generated.

The only way I've found to work around this issue is to completely delete the Nonstop Backup, and set it up again from scratch with the additional exclusion.

Is there a fix or workaround available? I really don't want to have to recreate my Nonstop Backup, enter all of the exclusions again, and wait hours for it to complete.

The reason I want to add the exclusion in the first place is that Nonstop Backup is messing with the licensing mechanism in the AQtime product, preventing that product from being able to register itself and run properly.