Very long loading time only when hosting a Listen Server (2+ minutes, Singleplayer loads in 5 seconds)

Development Programming & Scripting Blueprint
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Hi everyone,

I’m experiencing a very strange issue in UE5 and I haven’t been able to figure out what’s causing it.

The issue

  • Single Player: The map loads in about 5 seconds.
  • Listen Server (Host): The exact same map takes around 2 minutes and 15 seconds before I can play.
  • This happens even when I’m the only player. No clients are connected.

During those 2+ minutes:

  • The screen shows the default Unreal loading indicator (three dots in the bottom-right corner).
  • No HUD is created.
  • The world appears partially loaded.
  • After exactly ~2:15, everything suddenly becomes normal and the game starts.

Additional information

  • Using ServerTravel(MapName?listen).
  • Seamless Travel is disabled.
  • Different GameModes are used for the menu and gameplay maps.
  • The gameplay map uses World Partition.
  • The project also uses Runtime Virtual Textures (RVT).
  • This only happens in multiplayer (Listen Server). Single Player loads normally.

What I’ve already tried

  • Disabled Seamless Travel.
  • Added a loading screen plugin (the issue still exists).
  • Tested on high-end PCs.
  • Since Single Player loads in 5 seconds, I don’t think it’s simply a hardware performance issue.

My question

Has anyone seen a Listen Server take exactly 2+ minutes before the HUD appears?

Is there any known timeout, World Partition setting, networking initialization, or ServerTravel behavior that could explain this?

Also, what would you check first to diagnose this kind of issue?

Any ideas would be greatly appreciated.

Thanks!

2

Hey @BioFrost.in how are you?

It seems that this issue happens because the server side of World Partition is defaulted to force-loading every single streaming cell in the entire map, synchronously, before gameplay is considered ready, regardless of whether any player controller exists as a streaming source yet.

Your ~2:15 isn’t a network timeout at all, it’s simply how long it takes to synchronously stream in literally every cell of your map before the server considers itself “ready,” which is also why the HUD/loading indicator hangs the whole time and then everything “suddenly” pops in at once. It’s consistent because it’s deterministic disk/CPU work, not a race condition.

Here you have some articles that could help to understand it better, and solve it:

Hope this helps!

3

Thank you so much, wp.Runtime.EnableServerStreaming has solved may problem. :slight_smile: