So, it can't find the dbus session address file. This can happen occasionally with my builds, or it will happen continously with a 3rd party ppa that I used to use. I'd like to verify the source of your omxplayer package.
Can you run:
apt-cache policy omxplayer | pastebinit
The OMX_Player controls the rpi media software omxplayer. It is a new player that is on the rpi only.