Before inserting the USB into your computer first go to the Flashforge website and download the latest Firmware from the firmware section.
Step 1.
The first step is to ensure that you USB stick if formatted as 'FAT32'. Plug the USB into a computer, right click the USB Icon and select 'Format'. Make sure 'FAT32' is selected, then click 'format'.
Step 2.
Put the firmware file you downloaded onto the USB you just formatted. Make sure it is not in a folder, it needs to be in the base or root of the drive.
After copying, with the 5MPro turned off, insert the USB and then power on the printer. If you have followed the steps correctly you should see the following message on the printer screen.
Once competed, you will be prompted to reboot the machine. Hold the power button in for 10 seconds to do so. After rebooting the printer will finalise the new firmware installation.