Hi @sam,
Please refer to the following ideas:
When you updated the firmware on the HL7812 did you complete the steps outlined in the HL78 Series Firmware Update Methods. If not, please try again, attached link: HL78 Series Firmware Update Methods
Can you describe the steps you took as well as the full log when the update failed?
Also, if possible, could you please update the firmware on Windows to see if the issue still occurs?
Thanks,