The Original Prusa MK4/MK3.9 is showing the message: "Overcurrent detected on connected USB device, disconnect it."
Error name: USB Device Overcurrent
Error code: #13307 (MK4) #21307 (MK3.9)
The error is shown when there is an issue with the USB drive connected to the printer. In case you are using a USB-to-USB cable to connect the USB drive, the cable might also be causing the issue.
Replace the USB drive to use on the printer. Ensure that the replacement USB drive is formatted to FAT32 before operating it on the printer for the first time.