I used one of these at a bike shop I used to work at while a student, and I had to go and uninstall the printer from the computer and reinstall it with new updated drivers in order to fix this problem, also restart the printer spooler service and you should be in business.
Our Zebras periodically have the label size in the physical zebra configuration go wonky and we have to back and re-setup the label sizes. This happens to us about once every two or three months on random zebra printers. (We have about 15 company wide.) If the label size is incorrect it will just spit out blank labels.
Not sure if it was recommended but I don't want to read everything here. Zebras for me have been notorious for this and oddly enough it ends up being a driver issue half the damn time (strange). Uninstall and reinstall the drivers for your device. 2b1af7f3a8