I'm just making sure on this as last I checked I actually had issues running KMQ2 and Coop or Die.

Well, as far as I know, it should work. Someone (DeeKae) also told me that you may actually play "The Premonition of Angron" map serie by using KMQ2, as the game won't overflow anymore.

Also, in case other players can't connect to you (even after you opened the proper ports on your router if needed), you should use this command: "set net_compatibility 1".

KMQuake2 actually works with Coop or Die. But you have to consider the following:

First of all, you have to download the Coop or Die support DLL from Knightmare's site and place it in your coopordie folder.

1) Using KMQ2 as a client (you just join other people's servers)

You are able to connect to any Coop or Die server, that is actually reachable (opened ports if behind a router - but that is common sense). You have to select the protocol which KMQ2 is supposed to use depending on which Q2 Client the Host is using.
If the server (host) is using KMQ2 too, then you have to use protocol 56 (which is the default in KMQ2). So you should see any KMQ2 server in the server list in the Multiplayer menu right from the start (well ... it takes some seconds till they actually appear).
If the Host is using another client (eg. Classic Q2 3.20, R1Q2) you will have to switch to protocol 34 in order to be able to join. You can do this either in the server list of KMQ2 or via the console command "cl_servertrick 1".
Usually KMQ2 shows all available servers and adds a remark behind each regarding the protocol it is using. Switch protocol if the server you want to join has such a remark.

2) Using KMQ2 for running a Coop or Die Server (You want to let others join your server)


I take it as given that you opened all the regarding ports to make your server reachable. Now the most important thing about KMQ2 as a server:

Only players using KMQ2 are able to join a KMQ2 server!

That means most of the other players will not be able to see and join your server. The reason for this is that all the other clients (Q2 3.20, R1Q2, ...) cannot handle servers using protocol 56. Keep that in mind and consider using another Q2 Client for running a server. The Coop or Die community is already pretty thin and using KMQ2 as a server locks out all other non-KMQ2 users from your server.
But it is OK if you are planning to play just with your selected KMQ2-using buddies anyways.

The "Premonition of Angron" series can indeed be played by using any client that has built in the fix for the sound overflow error (which occurs on map1 of this series mostly as soon as the first Gunner throws the first grenade at you).
So far I have tested the follwoing clients which do not crash because of sound overflow error: Q2 Clients v3.23 and v3.24 (both from Knightmare - you can get the latter one from his KMQ2 site in the download section), KMQuake 0.20 b3.

Have fun.

Update 2013-09-11:

I have just figured out that R1Q2 crashes with the "index overflow for sounds" error on the Angron map series (just like the Classic Q2 Client 3.20 and EGL). Therefore I have to scratch it from the list of mentioned clients that do not crash.
At the moment it seems only the Q2 Clients v3.23 and v3.24 as well as KMQuake2 are able to run the Angron maps without crashing.
I have not tried AprQ2 v1.211 yet - maybe this is another client capable running these maps.
Could not test Quake2Max v0.44 and Yamagi Q2 5.11 as both do not run on my Win7 32Bit OS.
Feel free to post your experiences.

wat
Well, that's some good explanation over there.

It looks like we've got a KMQ2 veteran among us .
tl;dr

I should actually try finishing the mission with Mik1 obviously, as this topic reminded me about the possibilty to actually play those interesting-looking serie.