For persistent issues on models like the RZ or EZ series, technicians use to recalibrate the drum's home position or clamp angle:
Slide the drum back into place and press the [START] key to clear the message. Troubleshooting False Errors riso error a16-525
The typically occurs on EZ, RZ, and SF series machines. It indicates that the machine is "awaiting for the master to be removed from the drum" . Essentially, the printer believes a used master is still attached to the print cylinder and must be cleared before a new one can be created. Quick Fix (Manual Removal) Open the front cover and pull out the print drum. For persistent issues on models like the RZ