I realize that this is an old posting, but I am having this same problem.
If I set the Vapour Barrier = membrane layer = 0 thickness
==> "There myst be at least one layer with non-zero thickness"
??? curious response since the thickness is set to 0
If I set the Vapour Barrier = membrane layer = 1.6mm thickness
==> "Error" Row _: 'membrane layer' function requires zero thickness"
??? frustrating, but it won't allow me to set is to 0 (or 'zero')
The only thing I have found that I can do is not use the Membrane Layer function and call my vapour barrier a Thermal/Air and give it a minimal width of 1.6mm.
How do I address this glitch? Is it me or the software?
The first error message: "There must be at least one layer with non-zero thickness" occurs if the membrane layer with zero thickness is the only layer in the wall type.
The second error message: "Error" Row _: 'membrane layer' function requires zero thickness" occurs when one of the layers, designated as membrane layer, does not have a zero thickness.
In summary, you need more than one layer in the wall type, if you want to have one of them as a membrane layer with zero thickness; and the other layer must have a value higher than zero.
I had the same problem. I did have two other layers in my wall definition. One was 5/8" sheathing and the other was a 1 1/2" stud (stud on side). I could not make anything work until I tried it again and deleted the membrane layer. Then it magically worked. Nothing else was changed. It seems like a glitch.