have you checked customerportal.solidworks.com > knowledge base? there are a couple of reports about this message.
in my experience this happens when you are using no penetration and bolt connections. and the issue happens when they aren't defined properly.
the other time i've experienced this is with a bad mesh.
either one, i'd recommend troubleshoot by removing the no penetration and going to bonded, removing the bolted connections and slowly building up your assembly so that you can eliminate variables until you solve the problem/find the cause.