The image you show implies to me they are trying to use a software license.
But you mentioned they have a codemeter license.
If they have a software license then I think it should have been returned to the license pool before updating the OS.
So maybe Archicad thinks it is a new machine and can no longer find the license.
It needs to be retrieved from the pool, and if it was never sent back there and is no longer available on the machine you as the local retailer should have the resources to retrieve the licence.
If they do indeed have a silver metallic codemeter USB license, then why is Archicad asking for a software license.
I would say contact your local distributor / support person, but I am sure you have already asked yourself these question.
Maybe a complete un-install and re-install Archicad.
One of the forum moderators. Versions 6.5 to 26 Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10 Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11
Then, when installing, in dialog box we have to tick the Kernel extension, then install and
Select the Security and Privacy
Click the Allow button next to the System software developer “WIBU-SYSTEM AG” was blocked from loading message. Then restart the machine. The codemeter key will work.