Hi,
To answer you questions as I checked the source and the serial numbers are expected to be unique as its generated based off the MAC address of the host NIC as I stated prior.
The default serial number assigned is in fact LKABCDEF and that may occur when the windows level calls to retrieve did not provide a number back at the OS level. So something may not be compatible with the NIC on that specific server.
Again, this is not something we can change, and you need to get the application to modify or eliminate this check for you to move forward.
Jeff