This occurs when you launch MillMax software and then insert the dongle after starting. When you try to create a DCC (Dashboard) by clicking on the DCC button, you get this error message. You must insert the dongle before opening the MIllMax software.
UPDATE: If you took a measurement when the dongle is an expired state, the file will be corrupted and give you this error message. You can send it to us to be repaired or you can do it yourself: https://www.taptest.co/fix-txf.html