Hi,
1 Its not really necessary for this campaign to have victory conditions! The Japanese have only one regular airfield in this campaign, so if the american capture this field, the winner will be the red party!
And the other way, when the american lost both of their carriers, the Japanese will win this campaign!
2 Your message problem is really strange! Which options have you activated in DCG?
3 When you uncheck "Primary objectives" works all as normal?
4 Maybe it has something to do with the "No instant success" option in IL-2?
Sorry, more questions then answers! 
1. When I generated this campaign previously the victory condition was to take Ngebescus point.
2. My dcg.ini (after few test I've just done, though settings are back as they were when error happened):
E:\Ubisoft\IL-2 Sturmovik 1946\IL2DCG\
E:\Ubisoft\IL-2 Sturmovik 1946\missions\campaign\um\DGen_X_Palaudoe2\
E:\Ubisoft\IL-2 Sturmovik 1946\
Three
Three
Default
Default
Moderate
Full
Full
Squadron Defaults
50 Kilometers
Default
Default
MassedBombers=True
FrontMovement=True
CopyMission=False
Dogfight=False
Coop=False
FBDActive=No
AutoGeneration=True
Primary=True
DSTimes=True
Paras=True
Briefing=True
ShipRoF=5.0
HistDates=True
IL2SCUse=False
LogFileDate=[11.09.2012 15:23:06]
Tracking=True
NoTransfers=False
Night=False
DGEN_Replacement=True
TankDG=True
TransitAlt=Default
TgtEgressAlt=Transit Altitude
TgtAlt=Transit Altitude
TgtIngressAlt=Transit Altitude
IPAlt=Transit Altitude
TgtIngressOffset=Default
IPOffset=Default
TOStepAltBox=Default
NormandyBase=False
Death=False
AirStarts=True
TOCircle=Only Escorts & Escorted
IECoordinates=Only Level Bombers Use
CruiseSpeed=Default
Language=English
GameID=1946
NGEN_Replacement=False
SingleMap=False
PalmTrees=True
RuSupplyRate=1/Squadron/Day
DeSupplyRate=1/Squadron/Day
TrackPlayerRanks=True
AircraftDowngrades=True
LinkMax=False
DataFiles=E:\Ubisoft\IL-2 Sturmovik 1946\IL2DCG\Data\
DeShipSkill=Rookie
RuShipSkill=Rookie
ShipSunk=False
ActiveFront=True
DDRoF=1.0
BridgeRepairTime=1 Mission
BornPlaceRadius=3000
TimePassage=Normal
ServerInfo=
ServerActive=False
Balance=Default
SCPlaneLimits=No
SCTimeLimits=No Time Limit
SquadronManagement=False
IngressSpeed=Default
FixedStartDates=True
CountStaticPlanes=Yes
VoteLevel=100
Radio=Campaign Default
RandomNoseArt=True
NoUserLoadout=False
BeachheadResets=False
MDS=False
RUProp=No
StaticPlanes=No Spawn
3. Yup
4. Maybe, I left it turned off.
Now for the mindf**k:
1. I tried launching those missions through FMB and they worked fine.
2. I generated this campaign at seperate account with all possible "Primary Objective" and "No instant success" combinations (both off, both on, first off, second off), each time I skipped the first mission (except both on) right at the beginning, before any messege appeared. All worked fine.
3. I also generated campaign with exactly the same settings and it worked fine.
4. There are only 2 differences between broken campaign and other generations:
I: in broken one for some reason I was chosen leader of flight no. 1 (and all 12 planes) in every missions (having captains under my command as 1st lieutnant). However I was also leader in FMB tests and it worked fine...
II: in broken campaign I changed ammount of fuel in my flights from 100% to 75% during campaign in DCG window, though I think it was after the problem first appeared.
What do you think? Maybe I should simply restart the campaign?