CollisionHandlerFloor and Polygons

I have a problem with a CollisionHandler.
My Prog:
A room class and a player class
The room class:

self.__model_room= loader.loadModel( 'res/' + self.ri.srcname )
#put it in the render tree
self.__model_room.reparentTo( render )
#self.__model_room.node().setIntoCollideMask( BitMask32.bit(1) )
#self.__model_room.node().setFromCollideMask( BitMask32.bit(1) )
self.__model_room.setCollideMask( BitMask32.bit(1) )

the player class:

groundRay= CollisionRay()
groundRay.setOrigin( 0, 0, 1000 )
groundRay.setDirection( 0, 0, -1 )
groundCol= CollisionNode( 'modelGroundRay' )
groundCol.addSolid( groundRay )
groundCol.setFromCollideMask( BitMask32.bit( 1 ) )
groundCol.setIntoCollideMask( BitMask32.bit( 1 ) )
groundColNodePath= self.__model.attachNewNode( groundCol )
self.floorHandler= CollisionHandlerFloor()
self.floorHandler.addCollider( groundColNodePath, self.__model )
base.cTrav.addCollider( groundColNodePath, self.floorHandler )

The error message I get:

:collide(error): Invalid attempt to detect collision from CollisionPolygon!

This means that a CollisionPolygon object was added to a
CollisionTraverser as if it were a colliding object.  However,
no implementation for this kind of object has yet been defined
to collide with other objects.

But my prog works…
Thanks Martin

It’s not evident in the code snippet above, but the error message means that one of the NodePaths you passed to addCollider() actually contained one or more CollisionPolygons, and not just a CollisionRay or CollisionSphere.