ServerTravel not working after opening a session


Since 4.16 ServerTravel is not working properly when a network session is started (it was working fine in 4.15 and previous versions).

If i call ServerTravel before starting a session, it works well.

If i call ServerTravel and then start a session, then subsequent calls to ServerTravel work well.

But if i first start a session and then try to call ServerTravel, the new map is not loaded and i get the following message in the logs:

LogGameMode: Not traveling because of network error

When i add this before calling ServerTravel:

AGameModeBase* ThisGMBase = GetWorld()->GetAuthGameMode();
if (!ThisGMBase->CanServerTravel(TargetMap, false))
	GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Red, TEXT("CAN'T TRAVEL"));

The “CAN’T TRAVEL” message is displayed, so CanServerTravel is failing somehow, but i couldn’t locate where the function fails, i get none of the LogGameMode messages from CanServerTravel, and i can’t find the “Not traveling because of network error” message in the GameModeBase class.

I found a few occurrences of this error message on the forum and on the answerhub but none helped me with this problem so far.

  • the autoconnect checkbox has no visible effect (same problem when checked and unchecked)

  • it doesn’ occur only in the packaged game, but also in the editor standalone game

To be complete i should add that i have no idea if it works or not in a packaged game because some other 4.16 regression currently forbids me to launch a packaged game (other bug report opened). And as i am using steam, i don’t have network in PIE, so currently i can only test in an editor Standalone Game.

Thanks for any help !