Every time I attempt to play a 4v4 mode in For Honor, I get hit with the following error after ~1-2 minutes of matchmaking.
A error occurred. Returning to main menu. (0004000004)

This does not happen in 1v1 modes. Similarly, I can play online in Skirmish and Domination vs AI... if I set matchmaking to off.

My NAT is Open.

Steps to Reproduce:
Launch For Honor
Launch Multiplayer
Select Dominion or Deathmatch PvP
Wait as matchmaking occurs
Error occurs.

Steps taken on troubleshooting list:
Port forwarded:
TCP: 80, 443, 13000, 13005, 13200, 14000, 14001, 14008, 14020, 14021, 14022, 14023 and 14024
UDP: 3074, 3075
Reset Hosts file
Disabled Startup Applications
Disabled Firewall

Steps to solve.
Set Computer as DMZ host.


Upon setting up my computer as a DMZ host, I initially received Network Error 0004000008. Upon noticing this was a different error code and attempting matchmaking again, I was successful. Obviously having my computer setup as a DMZ Host long term is a terrible idea from a security perspective, so I'd rather not do that! However, forwarding ports did not successfully resolve the issue. Any help in this matter would be appreciated, since as I mentioned previously, I do not want to set up my personal computer as a DMZ host long term.