Hi.
… my first post…
This thread is quite old but the problem still exists even in SUSE tumbleweed. And we probably found the reason and a possible solution today.
We had exactly the same problem as the original poster: “invalid configuration (“workgroup” set to ‘’, should be MADDANT)”
We found out that the GUI join runs a “net ads lookup -S schulung.local” in the background (schulung.local is my Active Directory domain).
And this fails becaucse it tries a DNS lookup for the parent domain “local” first which is not resolvable because schulung.local is our root domain and there is no DNS forwarding to some parent DNS server. Which is a normal situation in an isolated Active Directory network IMO.
We could solve the problem by creating an empty forward lookup zone for the domain “local” in our (Windows-) DNS-Server.
“net ads lookup -S schulung.local” runs fine after that and so does the domain join via sssd.
I would call this a bug in the net ads tool.
Regards, Andreas