Ahh success! Even with the NIS user. So should I remove the _copr_mikedep333-nx-libs-3.6.repo?
Uhm... that depends. If you want to keep staying on the Arctica testing version of nx-libs, then no.
If you want switch back the older nx-libs version as shipped by X2Go, then you'll need to uninstall all X2Go and nx-libs packages first, then remove this repository and reinstall x2goserver and x2goserver-xsession again. Be careful with that - X2Go's older version needs x2goagent explicitly, while Arctica's version requires x2goserver-x2goagent. Both packages are conflicting and the different versions require either one or the other.
X2Go will switch to Arctica's version in a short time (few weeks?) anyway. I'd suggest staying on what the workstation is on currently.
Mihai