Comment # 3 on bug 983939 from Wolfgang Bauer

Be aware that there was a problem with this in Tumbleweed recently:
http://lists.opensuse.org/opensuse-factory/2016-06/msg00113.html

Running "pam-config --add --systemd" manually should fix your system.

The problem itself has been fixed in newer snapshots (by reverting pam-config),
though just installing current updates will *not* change anything.

A fresh installation should work too, though.