Why am I getting a "license revoked" error when installing a license on RePC/SFF?

It's likely that you are trying to license hardware that we have blacklisted, particularly if you are using a version of tms_client earlier than 8.3.0.

Prior to TMS / tms_client 8.3.0, our licensing of x86 hardware was critically dependent on the mainboard manufacturer providing a DMI/SMBIOS product UUID (Universally Unique IDentifier) that is - as the acronym implies - universally unique.  Manufacturers will typically use a vendor-specific prefix combined with the MAC address of an onboard NIC for this value.  Unfortunately, some manufacturers (mis)configure their BIOSes to report the same dummy data for every board they produce - usually a set of sequential numbers such as 00020003-0004-0005-0006-000700080009 or 03000200-0400-0500-0006-000700080009.  Allowing multiple users to license such devices would cause a great deal of confusion, as you'd end up retrieving somebody else's license.  Consequently, as we become aware of non-unique UUIDs, we add license revocations to our database that will prevent users from licensing hardware using these serial numbers.

In TMS / tms_client 8.3.0, we added a fallback licensing scheme whereby customers can use MAC-address-based licensing - albeit with onerous restrictions - for devices on which a known-non-unique mainboard UUID has been detected.  However, if you are using tms_client and your hardware is using an obviously non-random UUID (e.g. 00030002-0004-0005-0006-000700080009) rather than a random string of hexadecimal digits (you can double click on the entry in TMS and scroll down to Serial Number - see screenshot below - to check this), then you will not be able to license that device for TLXOS.  Please upgrade to tms_client 8.3.0 or later.

Licensing using MAC addresses is undesirable for several reasons:

• You may have no network interface whatsoever (e.g. a standalone digital signage device).
• Your network interface may be on a removable card (PCI/PCIe/M.2/USB), in which case our product will end up being licensed to your NIC, not your PC. Obviously that is a bad thing if the removable NIC gets replaced or relocated for any reason.
• If you have turned off your mainboard NIC in the BIOS, the O/S may not be able to detect it.
• Your mainboard may have multiple ethernet interfaces, and the order in which they are detected by the O/S may vary depending on the BIOS configuration (and the O/S in use). You could then end up with an unlicensed device because you made a BIOS change.
• MAC addresses can be easily faked.
  • Some hardware will allow arbitrary MAC addresses to be set in the NIC's EEPROM (or the PC's BIOS).
  • Linux will allow arbitrary MAC addresses to be set in software.
  • Under some conditions, MAC addresses may be routinely altered by the O/S (e.g. interface teaming).

To mitigate these risks, our fallback licensing scheme will only permit you to license the MAC address of the "primary" interface, where "primary" means the interface with a default route (or in the absence of a default route, any non-loopback IPv4 route) with the lowest metric.  What that means is that the interface must be actually in use, and that in situations where both Ethernet and WiFi are connected, the Ethernet MAC address will be used.