I didn't see a forum for Instant Doors & Windows, so I am posting here instead.
Every time I make a door or window using the double-wall option, I get the following error:
"Can not insert back component. Back wall face was not found."
Instant Door and Window is a new script. It is now part of the Instant Architecture package. So if you have a subscription to Instant Architecture and would like this script, please download and install instantArchitectureInstall.rbz from your account