Can not apply material to an interior wall Layer

[DeLayDesign]

I'm waiting for Chief to give a proper answer to this issue, but has anyone else run into this error before?  I can't seem to find a work around for it.  I'm using a 'solid railing' with a 4" cmu wall; but because the CMU is the interior wall layer chief won't allow me to paint it.

[scottharris]

Can you post the plan or export the wall type?