I'm trying tostart a vnc server which is shipped with SLES 12 SP1, specifically, TigerVNC 1.4.3-11.1. The server starts, but, the window manager fails to start and I have an unusable VNC session. I was told that SLES 12 will fall back to software llvmpipe based rendering for GNOME 3 which is shipped with it, however it doesn't seem to work, something is wrong either in my config or, the use of llvmpipe is broken in SLES 12. The error I get in my vnc log is below:

gnome-session-is-accelerated: No hardware 3D support.
gnome-session-check-accelerated: Helper exited with code 256

** (process:883): WARNING **: software acceleration check failed: Child process exited with code 1

Any tips are appreciated.