If your cartridge was burn out, your UNI Pro battery will occur this error.
So, please install a brand new cartridge to have a try.
Check the UNI Pro shorted or not.
Please pull out your cartridge, and hit the fire button, if this still occur shorted error, means the battery shorted inside the circuit board.
In this situation, please contact shop you bought from.
Or you can go the shop you bought from, if don't know how to check your device.
Yocan UNI blinking 5 times troubleshooting