Clients lose connection during ServerTravel with OnlineSubSystem Steam


For our project we are using Steam as OnlineSubSystem. The connection to the listen server can be established. When ServerTravel is called on the server side, however, the clients lose the connection after about 20 seconds. During this time, our loading screen is shown as it should be.

This error does not occour, when testing with multiple instances of standalone game in the editor. There everything works (except this other issue). The Steam Overlay does not appear within the standalone game of the editor, though.

We are not using seamless travel. I found this other post in the answer hub about disconnecting clients with steam and I thought maybe the reconnection after the map has changed might cause the same problem. Therefore, I modified the UnregisterConnection function as proposed in this thread, but it did not solve our problem.

Furthermore, we are using this modified version of server travel.

Does anyone know, what might cause our clients to lose the connection?

I tested, if the modified version of the server travel function might cause the issue, but the connection loss happens although with the normal “server travel” version…

I double checked what the exact error message is:
The ENetworkFailure Enum (converted to String/user friendly name) returns only “ConnectionLost”.

I am still trying to figure out, what is causing the disconnect. If I understand the logs (Server and client logs attached) correctly, the issue appears after the server travel…

As it seams, Server Travel is only possible with Steam when you use Seamless Travel. We experienced the same problem as described in the question now with a new project in UE4.11.2 and, thus, continued our search for a solution. Altough seamless travel causes other problems for us with the current state of our game, Server Travel as such works just fine now.

Here are some links to questions concerning the same problem, which have been solved by using seamless travel:

I hope if someone else runs into the same issues, this helps a bit! :slight_smile:
However, if you have additional information on the topic, please feel free to comment below. Every bit of insight on the topic is welcome. :slight_smile: