x1 Can't Get Attic Trusses to Build?

[Zowie]

I have a 12/12 pitch, flat floor and flat ceiling but can't get the **** thing to build, is what's the trick?

Thanks for the hints.

I also tried editing the truss in cad management, but I can't get that truss to say as the truss that I edit. Once I move it it my editing goes away, and if I lock it my edited parts go away and if I block it my edited parts go away. How do you make your editings stick. Thanks very much, zowie