Thank you for the info! It seems they may have fixed the bug. After reading that it was a driver issue, i checked the drivers from the HP site. There was an update published less than a week ago. After installing that, it seems to work, with the exception that it seems to max out at 36" high....but the error is gone.

Hello, I recently bought qimage ultimate as a way to manage a few different printers. One of which is an HP Designjet T100 (really not a fan of HP Click). I can select the printer, and roll, but when I go to change the paper size from the list to user defined and click on the Auto roll length, I get an error: Printer selected is not valid. What am I doing wrong?