I had some different problems that the website helped fix. According to them, here is their suggestion:
When I click the print button, I get an error message about my "default printer".
Check to make sure that your printer is on and the cable is not loose. You may also get this error if your printer is set at low-resolution or draft mode. You have to be able to print at a resolution of 300-dpi in order for the coupons to be legible enough to scan at the store. And you cannot print to PDF or any other kind of electronic file format.
Link for other help ideas:
http://coupons.smartsource.com/mnmedia/BottomNavs/Troubleshooting.html