Reason wall won't join roof?

[t1.shep]

I seem to get this problem too often...
I have a wall below a roof (the roof overhangs the wall), but the wall will not join to the roof.
What are some common issues that prevents this from joining?
I get this error... See attached images for what is happening.

[Andre Carvalho]

Revit doesn't like to join objects (join, attach, create voids) when they overlap just a little or there's tinny little gaps between them. You can probably check these conditions at the valley between the two roofs.

Andre Carvalho

[Mike Sealander]

Try joining to the tall gable first, and then the lower shed roof. Sometimes that works.

[patricks]

Yeah I love how it DOES join them while the error message is up and the objects are colored orange, but it says it can't join them. I want to scream at it "but you just did it you piece of ^%$#$#&!!!!" :p

[t1.shep]

Yeah I love how it DOES join them while the error message is up and the objects are colored orange, but it says it can't join them. I want to scream at it "but you just did it you piece of ^%$#$#&!!!!" :p
I hear ya. I'll do it over and over thinking that maybe this time it will stick.