I recently updated Tumbleweed to the 20150821 snapshot and with the 4.1.6-1 kernel, it hangs up on boot. Here are the errors:
[OK] Started D-Bus System Message Bus.
[41.5593341] Failed to register name: Connection timed out.
[41.578319] Failed to set up API bus: Connection timed out
It stays there hanging for a bit on the above services, then hangs up permanently at:
A start job is running for WPA Supplicant daemon.
At this point I have to hit the reset button, as nothing else short of cutting the power will allow me to reboot. The strange thing, is that after it hangs up as I wrote above, my PC will then boot normally after pressing the reset button on my case. Then, when restarting from within KDE, it will hang up again. The behavior is very strange. I went back to the 4.1.5-1 kernel and things are back to normal.