5-axis robot singularity

What may be a singularity on 5-axis robot !?

I also was under impression, that singularity is possible only on 6-axis robot, and cannot understand its physical meaning on a 5-axis one.
Mine freezes by singularity, on jogging into the joint position 0,29.8,-71.6,73.6,-0.7.
The World coordinates are 1592,-0.3,-93.9,162,-88,162,FUT00, far enough from the robot and the face plate is not parallel but perpendicular to the base.
The tool frame is 0,0,300,0,180,0,NDB.