AmiTCP 3.x is really, really old and its Unix roots, as kolla notes, are very apparent and - in my opinion - extremely difficult to configure. What's happening during the installation is that it's asking you to define the root account, not provide unknowable credentials for a hitherto unknown root account. With that information undefined, that's probably why the login system is getting confused post-installation. The documentation should explain this, but I recall the AmiTCP 3.x documentation to be lacking, so perhaps it doesn't. I highly recommend any other TCP/IP stack. Roadshow is the newest one and its author, Olaf Barthel, is one of the best documentation writers on the planet.
@ kolla
The user/group stuff added to 3.2 is likely related to Envoy, which is where C:Owner and C:Group originally come from. If you're using the machine as an Envoy server you can allow/restrict files based on the client's username/group. These extensions have been semi-official for decades, so it's good they're finally formalized. Now if we could just get the rest of Envoy integrated into the OS...
