You are using DCG in the Ngen, online Campaign Mode.
I personaly hate this mode, and could never get into it.
You can however do Manual DCG Online Campaign, which is what I do when flying online with a buddy of mine at home.
(This is from Memory, Please Anyone Correct it if I missed something)
Set DCG to Online Coop (On The DCG Tool),
Start/Pick a Campaign (On The DCG Tool),
Hit Generate Missions (On The DCG Tool),
Now Open IL2, Go to Multiplayer & Start a Coop Server
Scroll down through the lists of Campaigns & Pick DCG
You should see One Mission Listed (As a Date),
:!: Ok here is the weird part I usualy have to go through.... :!:
Launch that Missions, and End it.
As in Spawn on the runway, then Quit the Mission with out shutting down your server.
Minimize IL2, and Open the DCG tool,
Now you can alter the campaign, skins, Airfield, all those neat things the DCG lets you do, and they will be saved.
Hit Generate Mission again, Re Open IL2, Refresh that Coop Mission List Page in IL2
(pick a random campaign then go back to the DCG missions),
you should see a Second Date, maybe the next day.
8) Now your Set, just fly your Missions with your Friends, after every mission you have to Minimize IL2 and Strike the Generate Mission Button on the DCG Tool to get your next mission on the list.