Can't host non vanilla missions.

[ghostnineone 10]

I can't seem to host any missions with mods in them. I hosted a vanilla DAP insurgency and my friend could join no problem. I put down a HAFM crate (a mod we both have that's up to date) and he gets kicked. It will kick him no matter what I put down. If he hosts, I can join and we can play no problem.

I don't know what could be causing this. Is there any way to look at the error messages that used to be generated that states why the person was disconnected? It's frustrating trying to pinpoint this problem with no idea what's causing it.