Wall connection problem

I, could you help me to make this wall connection working?

test.3dm (2.6 MB)

Hi @guillaume.dupas, what are you trying to do? join the two marked walls above that little roof, or get rid of the edge of that perpendicular wall of the facade?
In the first case, you may need to create a new wall on top of the roof gap. In the second case, if you just pull the endpoint of the perpendicular wall so it reaches the interior side of the facade, the edge should not appear anymore.

wall edge