UC400ETH no valid license key

[Nordwork]

I have UCCNC with a UC400ETH from Stepcraft.
But I keep getting the message that there is no valid license key. Of course, this was copied into the directory as prescribed. I tried it via a router but also directly (crossover cable). The ping works and when UCCNC starts, the blue LED flashes very briefly, but then the message comes back that no license key is available. The key number matches the one on the interface. Can it be that the key in the file is wrong?
Anyone have any ideas?

[cncdrive]

Yes, it is possible that the license key file is corrupted/broken.
Also verify the serial number of your UC400ETH with the UCx00 utility tool, you can find it in the UCCNC/Util folder to see if it matches the serial number of the license key.
If you can't get it work then please email us and we will resend you the license key file.