After connecting all clients to my lobby, I set a ServerTravel to a level, and it fails only in 4.16, works fine in 4.15… Set up a simple lobby and add a server travel to any level.
Testing as a single client does not show the problem, you need to have any sort of simple connected lobby
Are you using Steam? And have you tried messing with bSteamlessTravel, in your AGameMode class?
No steam, this is just a listen server setup for early development, and seamless travel can’t be used for in-editor testing (PIE)
I see these errors following the failed servertravel, but not every time
LogGameMode: Not traveling because of network error
LogNet: UNetDriver::TickDispatch: Very long time between ticks. DeltaTime: 0.01, Realtime: 5.44. IpNetDriver_3
LogNet: UNetDriver::TickDispatch: Very long time between ticks. DeltaTime: 0.01, Realtime: 5.44. IpNetDriver_5
LogNet: UNetDriver::TickDispatch: Very long time between ticks. DeltaTime: 0.01, Realtime: 5.44. IpNetDriver_4
LogNet: UNetDriver::TickDispatch: Very long time between ticks. DeltaTime: 5.44, Realtime: 0.01. IpNetDriver_3
LogNet: UNetDriver::TickDispatch: Very long time between ticks. DeltaTime: 5.44, Realtime: 0.01. IpNetDriver_5
LogNet: UNetDriver::TickDispatch: Very long time between ticks. DeltaTime: 5.44, Realtime: 0.01. IpNetDriver_4
I remade the basic network blueprints within a blank, new scene and it works as expected. So I did a little bit of digging and in the log this is the first thing that I see
On the working build
LogNet: Browse: 10.1.10.14//Game/startMap\par
On the failing build
LogNet: Browse: 127.0.0.1//Game/Maps/MainMenu\par
so the failing one is trying to talk through localHost and the working one is the IP of the test machine. But there is no specific network code for that setup and no setting that I can find for localHost vs IP
Further up in the log, before it even tries to start I can see this
LogGameMode:Display: Match State Changed from WaitingToStart to InProgress
LogGameState: Match State Changed from WaitingToStart to InProgress
LogLoad: Took 1.013578 seconds to LoadMap(/Game/Maps/Lobby)
LogNet:Warning: Network Failure: GameNetDriver[FailureReceived]: Host closed the connection.
LogNet:Warning: Network Failure: GameNetDriver[FailureReceived]: Host closed the connection.
LogNet:Warning: Network Failure: GameNetDriver[FailureReceived]: Host closed the connection.
LogNet: NetworkFailure: FailureReceived, Error: ‘Host closed the connection.’
There’s nothing calling a connection closed, but it goes from 127.0.0.1 to 10.1.10.14 somehow. There is literally nothing in there that should be resetting the net code
looking through the logs it seems like it starts on 127.0.0.1, loses connection, re-accepts the connection at 127.0.0.1 but tries to connect to 10.1.10.14
Fixed it: The upgrade from 4.15 to 4.16 caused the setting “Auto-connect to server” to be reset. When it starts up, auto-connect tries to create a link on localhost at 127.0.0.1 when the server is started and the clients join it fails the connection and resets the IP to 10.1.10.14 and connects the clients to the listen server, but when the ServerTravel is called the networking fails…
And what is the solution?
At me on 4.18 the same problem. The decision has not been found yet.
A video of what is mentioned above 