Since Stage 4.0 no longer provides a laser interface the example config files like vfh.cfg no longer work.
Stage plugin: 6665.position2d.0 is "r0"
Stage plugin: 6665.laser.0 is err: error: stage driver doesn't support interface type 6
error : Initialization failed for driver "stage"
error : failed to parse config file vfh2.cfg driver blocks
As far as I can tell, using the rangetolaser driver and changing the stage driver to provide ranger:0 instead of laser:0 makes it work (see attached file).