FYI, I just noticed this forum thread, which seems to be about exactly the same issue: https://forums.opensuse.org/showthread.php/519585-20160820-Plasma-5-Breeze-Login-Screen-Freezes Most importantly, the poster wrote today that yesterday's Tumbleweed updates fixed it for him, so try updating your systems first. I have to say though that I'm not really seeing any possibly related change in yesterday's 20160901 snapshot release: http://lists.opensuse.org/opensuse-factory/2016-09/msg00131.html Except maybe the gcc update, which also caused many things (including sddm, Mesa and Xorg/the drivers) to be rebuilt.