yes, that was the case ... an arched doorway, csg subtracted from a wall guys, your help is fantastic and indirectly proportional for my increasing frustration (ehm, here my English knowledge fails, I have to confess, hahaha)
dmap shows one (irritating) warning: brush primitive 148 on entity 0 is degenerate how can I locate / select this special brush in darkradiant? in other words I don't know what I made where wrong
tbh me don't know how to convert a brush into an entity .. each time I try to select another class(name) from the entity list, it is not accepted and the brush remains at class worldspawn.
hiyas ... I attached ('bind') a ladder model to a trapdoor, that is working only the ladder was not climbable. After creating the invisble brush with climbable texture ('ladder') and bind-ing this brush also to the trapdoor, dmap shows an error: tried to bind world to 'Trapdoor' how can I bind a brush to a moving (rotating) object?