v1.6 COOP CTD as soon as I click "deploy"

Hi guys, thanks for taking your time to answer me.

Me and my friends can't play coop because we can't join each other's servers. We can host and play with bots just fine, but as soon as one of us try to join the server, the game CTDs as soon as we click "DEPLOY" (ctd is from client-side only, server keeps running fine). This happens with everyone as we all took turns hosting the server.

We're all using offline accounts.

Thanks for the help!