extrude command

 From:  BurrMan
2998.2 In reply to 2998.1 
Hi Andras,
Your points are not touching in this area. If you turn on control points for these 2 entities and then window select that corner point (Actually 2 points):

Then switch to the right view and hit the reset view icon you will see this:

Go back to the 3d view and select the little vertical lines bottom point and snap it to the horizontal end point and it will extrude as solid.

EDITED: 19 Jun 2012 by BURRMAN