Errors when hosting listen server on Mac

Development Platform & Builds
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1

Hi, I’m having trouble with getting Mac w/OSS working, it seems to work mostly fine when I host with Windows, but strangely, when I host with Mac, I cannot seem to join. It seems to try for a while and then time out after a couple minutes:

[2026.08.16-00.14.59:555][702]LogNet: Warning: UNetConnection::Tick: Connection TIMED OUT. Closing connection.. Elapsed: 120.01, Real: 120.01, Good: 120.01, DriverTime: 120.01, Threshold: 120.00, [UNetConnection] RemoteAddr: 76561199057267301:7777, Name: SteamSocketsNetConnection_2147482305, Driver: Name:PendingNetDriver Def:GameNetDriver SteamSocketsNetDriver_2147482368, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID
[2026.08.16-00.14.59:555][702]LogNet: Error: UEngine::BroadcastNetworkFailure: FailureType = ConnectionTimeout, ErrorString = UNetConnection::Tick: Connection TIMED OUT. Closing connection.. Elapsed: 120.01, Real: 120.01, Good: 120.01, DriverTime: 120.01, Threshold: 120.00, [UNetConnection] RemoteAddr: 76561199057267301:7777, Name: SteamSocketsNetConnection_2147482305, Driver: Name:PendingNetDriver Def:GameNetDriver SteamSocketsNetDriver_2147482368, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID, Driver = Name:PendingNetDriver Def:GameNetDriver SteamSocketsNetDriver_2147482368
[2026.08.16-00.14.59:555][702]LogNet: Warning: Network Failure: PendingNetDriver[ConnectionTimeout]: UNetConnection::Tick: Connection TIMED OUT. Closing connection.. Elapsed: 120.01, Real: 120.01, Good: 120.01, DriverTime: 120.01, Threshold: 120.00, [UNetConnection] RemoteAddr: 76561199057267301:7777, Name: SteamSocketsNetConnection_2147482305, Driver: Name:PendingNetDriver Def:GameNetDriver SteamSocketsNetDriver_2147482368, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID
[2026.08.16-00.14.59:555][702]LogNet: NetworkFailure: ConnectionTimeout, Error: ‘UNetConnection::Tick: Connection TIMED OUT. Closing connection.. Elapsed: 120.01, Real: 120.01, Good: 120.01, DriverTime: 120.01, Threshold: 120.00, [UNetConnection] RemoteAddr: 76561199057267301:7777, Name: SteamSocketsNetConnection_2147482305, Driver: Name:PendingNetDriver Def:GameNetDriver SteamSocketsNetDriver_2147482368, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID’
[2026.08.16-00.14.59:555][702]LogNet: UNetConnection::Close: [UNetConnection] RemoteAddr: 76561199057267301:7777, Name: SteamSocketsNetConnection_2147482305, Driver: Name:PendingNetDriver Def:GameNetDriver SteamSocketsNetDriver_2147482368, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID, Channels: 3, Time: 2026.08.16-00.14.59
[2026.08.16-00.14.59:555][702]LogNet: UNetConnection::SendCloseReason:
[2026.08.16-00.14.59:555][702]LogNet: - Result=ConnectionTimeout, ErrorContext=“ConnectionTimeout”
[2026.08.16-00.14.59:555][702]LogNet: UChannel::Close: Sending CloseBunch. ChIndex == 0. Name: [UChannel] ChIndex: 0, Closing: 0 [UNetConnection] RemoteAddr: 76561199057267301:7777, Name: SteamSocketsNetConnection_2147482305, Driver: Name:PendingNetDriver Def:GameNetDriver SteamSocketsNetDriver_2147482368, IsServer: NO, PC: NULL, Owner: NULL, UniqueId: INVALID

Very strange: I am also getting this error on the Mac when I start the server:

LogOutputDevice: Warning:

Script Stack (0 frames) :

LogOutputDevice: Error: === Handled ensure: ===
LogOutputDevice: Error:
LogOutputDevice: Error: Ensure condition failed: PrecompiledData->FindDataID(this).IsValid() [File:./Runtime/MovieScene/Private/MovieSceneSequence.cpp] [Line: 130]
LogOutputDevice: Error: No precompiled movie scene data is present for sequence ‘Sequence’. This should have been generated and saved during cook.
LogOutputDevice: Error: Stack:
LogOutputDevice: Error: [Callstack] 0x0bf63538 WerewolfGame!UMovieSceneSequence::PostLoad()::$_0::operator()() const [UnknownFile])
LogOutputDevice: Error: [Callstack] 0x069eda8c WerewolfGame!UMovieSceneSequence::PostLoad() [UnknownFile])
LogOutputDevice: Error: [Callstack] 0x01597380 WerewolfGame!UObject::ConditionalPostLoad() [UnknownFile])
LogOutputDevice: Error: [Callstack] 0x017149b4 WerewolfGame!StaticDuplicateObjectEx(FObjectDuplicationParameters&) [UnknownFile])
LogOutputDevice: Error: [Callstack] 0x0387d924 WerewolfGame!AActor::CreateComponentFromTemplate(UActorComponent, FName) [UnknownFile])
LogOutputDevice: Error: [Callstack] 0x04848380 WerewolfGame!USCS_Node::ExecuteNodeOnActor(AActor, USceneComponent, UE::Math::TTransform const, FRotationConversionCache const, bool, ESpawnActorScaleMethod) [UnknownFile])
LogOutputDevice: Error: [Callstack] 0x048ca86c WerewolfGame!USimpleConstructionScript::ExecuteScriptOnActor(AActor, TInlineComponentArray<USceneComponent, 24u> const&, UE::Math::TTransform const&, FRotationConversionCache const, bool, ESpawnActorScaleMethod) [UnknownFile])
etc

I’m using 5.8, xcode 26.3, any help would be appreciated, thank you!

2

Hello there @FatalError418!

Checking with my peers, you are indeed dealing with two different issues here, and there are a few actions to take for each one:

  • First, your connection times out after 120 seconds, and since the same setup works as intended in Windows, then the issue has to be related to one of Mac’s security requirements

  • Considering Xcode is being used here, please make sure that your entitlements file includes all the relevant permissions for the connection

  • Also, check your firewall settings, your project must be allowed to receive incoming connections

  • Second, the “Ensure condition failed” error, that one means UE was unable to find data required to cook, which could be due stale or corrupted assets being present in cache

  • Go to your project’s main directory, and delete folders Saved, Intermediate, and DerivedDataCache, in order to force UE to run a new cook, then test again

4

I have both .server and .client entitlements (and i have removed sandboxing). Firewall is turned off on both computers. After recloning and repackaging i got rid of the ensure condition errors, which is great, but sadly did not actually fix the network issue.

Also, I have found a new error, it seems like the mac is not using SteamSockets, and is instead using default IP connection!
It gives me: “Unable to load SocketSubsystem module SteamSockets”.
But I’m not quite sure how to make Mac be able to load SteamSockets. It must be something to do with the entitlements, I suppose? Am I missing one?

5

Actually nvm, when I checked again I see those ensure errors again, though I am pretty sure they weren’t there when I checked earlier..?

6

Hello again!

That’s an interesting find, if SteamSockets is not working as intended, that could explain the whole network issue. So, the next action here will be to ensure that the feature is properly setup, by checking it’s related plugins:

Also, check your .ini files and confirm they include definitions for “SteamSockets.SteamSocketsNetDriver”. After that, make another test, and see if you can join. If not, look for the SteamSockets error, in case it’s info has changed, and we can continue from there.

7

SteamSockets does appear to be fully set up, at least I thought, but then I looked at my packaging logs on Mac:

LogModuleManager: InternalLoadLibrary: ‘SteamSockets’ (‘/Users/Shared/Epic Games/UE_5.8/Engine/Plugins/Runtime/Steam/SteamSockets/Binaries/Mac/libUnrealEditor-SteamSockets.dylib’)

LogOnline: Display: STEAM: OnlineSubsystemSteam::Shutdown()

LogSockets: SteamSockets: Disabled due to no Steam OSS running.

It seems like I have found an error message after weeks of looking…
But, the strangest thing, I’m getting this same error on windows as well:

LogModuleManager: InternalLoadLibrary: ‘SteamSockets’ (‘C:/Program Files/Epic Games/UE_5.8/Engine/Plugins/Runtime/Steam/SteamSockets/Binaries/Win64/UnrealEditor-SteamSockets.dll’)

LogOnline: Display: STEAM: OnlineSubsystemSteam::Shutdown()

LogSockets: SteamSockets: Disabled due to no Steam OSS running.

I guess I have not set up steam sockets right… Idk.

FYI steam sockets DO successfully start up on the Windows log. But something about my integration of steamsockets must be wrong.

Also, here is my config file, if it helps in any way:

DefaultEngine.ini (29.1 KB)

8

Thanks for the follow up!

Looking through your .ini file, I agree that SteamSockets seems to be fully setup. All components are present, the key thing here is that error you found, “SteamSockets: Disabled due to no Steam OSS running”.

This means that the problem is not in your config files, but something between your system is failing to setup a Steam session for SteamSockets to attach in the first place. And when SteamSockets can’t find anything, it justs shuts itself down.

Checking with my peers, there are a few paths to take here:

  • Something’s wrong with the steam client itself, it’s either not responding, or not logged in. This is as simple as opening Steam, and ensuring it’s up and running durint testing. Fully logging off, then back on, could clear up issues with the app

  • Another common steam issue, is the steam_appid.txt file. Whenever you are testing a game outside of Steam, that needs to reach Steam, the folder containing the .exe file needs to a steam_appid.txt right next to it, and that .txt contains your application’s ID number, and only that (let’s say your ID is 1753, then that’s the only line in the file)

Please test these two topics, and share an update here with your results!

9

Ah actually I realised that that log was just the editor log, so it would make sense why there is that “error” ,and if I look through the actual mac logs it looks totally fine, which is the strangest thing. Yet the two connections never see eachother. If I try on two macs (no crossplay) I get the same issue there two, hosting on either. I have some logs, if it helps:

Hosting on Mac: Log file open, 08/19/26 14:08:27LogInit: Running DelayedAutoRegister Phase Sta - Pastebin.com
(trying) to join on Windows: Log file open, 08/21/26 10:18:13LogWindows: Failed to load 'aqProf.dll' (GetLa - Pastebin.com

10

Thanks for the sending the logs! Checking through them, I do see one key factor, regarding the engine version for each build:

Mac: 1. LogInit: Engine Version: 5.8.1-56057345+++UE5+Release-5.8
Windows: 1. LogInit: Engine Version: 5.8.0-55116800+++UE5+Release-5.8

Per these entries, your Mac build is compiled using UE 5.8.1, while your Windows build is compiled with UE 5.8.0. This mismatch could be the cause of the whole problem, as the build using 5.8 won’t pass the compatibility check when linked with the 5.8.1 one. I think it’s worth rebuilding both platforms to ensure they are using the same UE version.

12

I updated on windows, rebuilt and recloned on mac (rebuilding ofc), still having the same issue. But I did get more logs:

Windows: Log file open, 08/22/26 15:56:42LogWindows: Failed to load 'aqProf.dll' (GetLa - Pastebin.com
Mac: Log file open, 08/22/26 15:56:30LogInit: Running DelayedAutoRegister Phase Sta - Pastebin.com

13

Excellent, we are making some progress here. Reading those new logs, there are some critical lines to consider. From the Mac log:

LogNet: UNetConnection::PendingConnectionLost. RemoteAddr: 76561197994937744:7777, … IsServer: YES

This means that a connection attempt was succesful, between your Mac and Windows machine, with a matching Steam ID. The link managed to create an object, referencing a joining player. So, the machines can see each other now.

As for why they are losing connection, we need to see the Windows log:

STEAM: Server response IP:187.144.145.100
STEAM: Removed incompatible build: ServerBuildUniqueId = 0x00000000, GetBuildUniqueId() = 0x03490400

…

Async task ‘FOnlineAsyncTaskSteamFindServers bWasSuccessful: 1 Results: 0’ succeeded in 2.792909 seconds

There are multiple entries of this server response with an incompatible build, followed by a “FindServers” task. The previous logs showed a “FindLobbiesForFindSessions” task being used. If the whole hosting server is lobby based, then it shouldn’t be looking for public IPs that are not related to lobby discovery. So, I would confirm the connection methods being used in the build.

There’s one more entry to check, back in the Mac log, which shows a Sequence error:

Ensure condition failed: PrecompiledData->FindDataID(this).IsValid()
No precompiled movie scene data is present for sequence ‘Sequence’.

This means that your player’s spawning is hitting a broken reference, inside the “Sequence” component. While this is not directly tied to the connection issue, it may generate problems down the line. To fix it, open your player’s BP, and use the Reference Viewer to look for any broken ties inside, either to itself, or one of its Childs. Once it’s located and fixed, I would suggest clearing up the Mac build’s cache, followed by a rebuild.

14

(post deleted by author)

15

I think the reason why its finding other public ips is that bc I’m using appid 480 (the debug appid) there are other people also using it. Of course, the games themselves are different, so it discards the result due different appids. Note that I see the mac as joinable, its just it times out trying to join.