License server error 500 on Qnap

[simoncn]

I have checked the license server logs. This problem is caused by corrupted serial number/MAC address information in the device firmware. You can confirm this by opening Control Panel and selecting System Status. You will see that a corrupt value is shown on the System Information tab for Serial number and an incorrect value (00:00:00:00:05:09) is shown on the Network Status tab for MAC address.

The same thing happened to another user a few months ago. It appears to be caused by something going wrong with a firmware update. He contacted QNAP support and they were able to fix the problem for him.