Unreal 5.4 problem with a packaged game! Server spawns the character and client disconnecting with 'Failed to load package' error.

[Ocean.Heart]

Hello, guys. That problem killing my days so you are my last hope.

I usually test my multiplayer project by running a local server with bat file with -server parameter and joining same way with -game. And sometimes for the group testing I package the game for my friends to join.

Everything worked fine in 5.3 but in 5.4 I stuck with this problem. PIE and -game launching works fine. It occurs only in packaged game.

I connect to the server and everything is ok but when it spawns a player character the client got immediately disconnected with the “Error ‘Failed to load package ‘’’. Exiting.” And it happens not only in my project but in all the starter template projects at 5.4. So I recreated this problem in a ThirdPersonTemplate project.

There’s some details that I should mention:

• I tried to spawn with same logic the “pawn” class and possess it and everything fine. This problem occurs only when server spawns “character” class.
• I tried all the different packaging ways by the default tool and project launcher. And Shipping / DebugGame / Development configuration doesn’t matter.
• My packaging process have no warnings.
• The client and server have the same version of a game / content. I’m using “full rebuild” option and tried to force that character asset to cook with “Additional asset directories to cook”.
• I tried reinstalling UE / Visual Studio and clearing the project / engine cache.

So… here is the logs. Please, help😥

Server:

Client:

[SeGuVeGa]

I have the same exact issue but for me it appears when i execute Console command Open Ip : port
do you manage to solve it?
LogLoad: Took 0.091811 seconds to LoadMap(/Game/Maps/UEDPIE_0_EscapeMap)
LogGlobalStatus: UEngine::LoadMap Load map complete /Game/Maps/UEDPIE_0_EscapeMap
LogGlobalStatus: UPendingNetGame::TravelCompleted Pending net game travel completed
LogNetPackageMap: Warning: GetObjectFromNetGUID: Network checksum mismatch. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[17]Default__FPlayer, 3537320609, 36963642
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object from path. Path: Default__FPlayer, Outer: /Script/EscapeAndBuild, NetGUID: 17
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[17]Default__FPlayer
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor. Unresolved Archetype GUID. Path: Default__FPlayer, NetGUID: 17.
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor Unable to read Archetype for NetGUID 6 / 17
LogNet: Warning: UActorChannel::ProcessBunch: SerializeNewActor failed to find/spawn actor. Actor: None, Channel: 4
LogNetPackageMap: Warning: GetObjectFromNetGUID: Network checksum mismatch. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[23]SpectatorPlayer, 3234550367, 2147295253
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object from path. Path: SpectatorPlayer, Outer: /Script/EscapeAndBuild, NetGUID: 23
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[23]SpectatorPlayer
LogNetPackageMap: Warning: GetObjectFromNetGUID: Network checksum mismatch. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[25]Default__FSkeleton, 2788123537, 1104374258
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object from path. Path: Default__FSkeleton, Outer: /Script/EscapeAndBuild, NetGUID: 25
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[25]Default__FSkeleton
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor. Unresolved Archetype GUID. Path: Default__FSkeleton, NetGUID: 25.
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor Unable to read Archetype for NetGUID 12 / 25
LogNet: Warning: UActorChannel::ProcessBunch: SerializeNewActor failed to find/spawn actor. Actor: None, Channel: 6
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object from path. Path: Default__FSkeleton, Outer: /Script/EscapeAndBuild, NetGUID: 25
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[25]Default__FSkeleton
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor. Unresolved Archetype GUID. Path: Default__FSkeleton, NetGUID: 25.
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor Unable to read Archetype for NetGUID 20 / 25
LogNet: Warning: UActorChannel::ProcessBunch: SerializeNewActor failed to find/spawn actor. Actor: None, Channel: 7
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object from path. Path: Default__FSkeleton, Outer: /Script/EscapeAndBuild, NetGUID: 25
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[25]Default__FSkeleton
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor. Unresolved Archetype GUID. Path: Default__FSkeleton, NetGUID: 25.
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor Unable to read Archetype for NetGUID 28 / 25
LogNet: Warning: UActorChannel::ProcessBunch: SerializeNewActor failed to find/spawn actor. Actor: None, Channel: 8
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object from path. Path: Default__FSkeleton, Outer: /Script/EscapeAndBuild, NetGUID: 25
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[25]Default__FSkeleton
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor. Unresolved Archetype GUID. Path: Default__FSkeleton, NetGUID: 25.
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor Unable to read Archetype for NetGUID 70 / 25
LogNet: Warning: UActorChannel::ProcessBunch: SerializeNewActor failed to find/spawn actor. Actor: None, Channel: 27
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object from path. Path: Default__FSkeleton, Outer: /Script/EscapeAndBuild, NetGUID: 25
LogNetPackageMap: Warning: InternalLoadObject: Unable to resolve object. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[25]Default__FSkeleton
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor. Unresolved Archetype GUID. Path: Default__FSkeleton, NetGUID: 25.
LogNetPackageMap: Error: UPackageMapClient::SerializeNewActor Unable to read Archetype for NetGUID 78 / 25
LogNet: Warning: UActorChannel::ProcessBunch: SerializeNewActor failed to find/spawn actor. Actor: None, Channel: 28
LogNet: Error: UEngine::BroadcastNetworkFailure: FailureType = NetChecksumMismatch, ErrorString = GetObjectFromNetGUID: Network checksum mismatch. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[17]Default__FPlayer, 3537320609, 36963642, Driver = Name:GameNetDriver Def:GameNetDriver IpNetDriver_0
LogNet: Warning: Network Failure: GameNetDriver[NetChecksumMismatch]: GetObjectFromNetGUID: Network checksum mismatch. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[17]Default__FPlayer, 3537320609, 36963642
LogNet: NetworkFailure: NetChecksumMismatch, Error: ‘GetObjectFromNetGUID: Network checksum mismatch. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[17]Default__FPlayer, 3537320609, 36963642’
LogNet: Error: UEngine::BroadcastNetworkFailure: FailureType = NetChecksumMismatch, ErrorString = GetObjectFromNetGUID: Network checksum mismatch. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[23]SpectatorPlayer, 3234550367, 2147295253, Driver = Name:GameNetDriver Def:GameNetDriver IpNetDriver_0
LogNet: Error: UEngine::BroadcastNetworkFailure: FailureType = NetChecksumMismatch, ErrorString = GetObjectFromNetGUID: Network checksum mismatch. FullNetGUIDPath: [11]/Script/EscapeAndBuild.[25]Default__FSkeleton, 2788123537, 1104374258, Driver = Name:GameNetDriver Def:GameNetDriver IpNetDriver_0
LogGlobalStatus: UEngine::Browse Started Browse: “/Game/Maps/MainMenu?closed”
LogNet: Browse: /Game/Maps/MainMenu?closed
LogNet: Connection failed; returning to Entry

[Fysez]

Having the same problem. I upgraded from UE5.1 to UE5.4, wasn’t getting this issue before.

Network checksum mismatch. FullNetGUIDPath: [126]BP_PlayerState_C_2147481901.[134]AbilitySystemComponent

This is on an entirely new PC so I have no idea how there could be a mismatch… rebuilt and re-validated files. Hmm…

[sfak4488]

Same problem here, any solutions?

[Austin_WGames (Austin James)]

i’d need to see actual log files in order to see actually thing, but one thing i know that is (for some reason) still an issue is handshake mismatching, workaround is to add this to your DefaultEngine.ini and then report back:

[ConsoleVariables]
net.CurrentHandshakeVersion=2
net.MinHandshakeVersion=2

if that works, let me know. if not i’d need to see logs to try to get the full picture. for context i went from 5.0 to 5.4 and had to do that.

[sfak4488]

clash_game5.log (484.9 KB)
clash_game5_2.log (231.3 KB)
clash_game5_2-backup-2024.05.25-13.16.22.log (202.0 KB)

This log is before I tried your solution

[Ocean.Heart]

@sfak4488

I tried your solution

Hey! Thank you for stopping by and trying to help!

I tried your solution but had no effect
Did that in my project and in default one also. Here the 4 logs before changes and 2 more logs with it.

Btw, I went to find info about new “rejecting game packet with invalid session id” warning and found this thread which seemed quite similar.

UE 5.1 Steam Sockets Problem

Hey all, I can’t get joining to work with Steam Sockets, and I’m pulling my hair out trying to figure out what’s going wrong. I’m on 5.3, with no Advanced Sessions plugin. When I try to join a LAN game with steam sockets, I just get kicked back to the menu. This is the log. I can join LAN games with steam disabled though… What am I doing wrong (Ignore FCTween warning, not relevant.) [image] DefaultEngine.ini [URL] GameName=<REDACTED> Port=27015 PeerPort=27015 Quer…

Server Log (my game).log (107.3 KB)
Client Log (my game).log (118.9 KB)

Server Log (default project).log (87.6 KB)
Client Log (default project).log (121.6 KB)

Server Log (default project - handshake).log (84.1 KB)
Client Log (default project - handshake).log (90.5 KB)

[sfak4488]

Same problem with me too, still not working, we need more help

[sfak4488]

There is a temporary solution, until Epic Games fixes it in the next update

by updating DefaultEngine.ini with

[ConsoleVariables]
net.IgnoreNetworkChecksumMismatch=1

Thanks to fysez for sharing the solution

Edit: Also if you are working on other platforms like Android, you need to copy the DefaultEngine configuration file and put it to the path Config\Android\AndroidEngine.ini

[NV_gnoowik]

You need to fix engine codes:

• In Character.h, FRepRootMotionMontage struct.
• (If you use gameplayability) In GameplayAbilityRepAnimMontage.h, FGameplayAbilityRepAnimMontage struct.

Try to mark NotReplicated on UPROPERTY or delete variable AnimMontage_DEPRECATED

In Character.h

#if WITH_EDITORONLY_DATA
    /** AnimMontage providing Root Motion */
    UPROPERTY(NotReplicated, meta = (DeprecatedProperty, DeprecationMessage = "Use the GetAnimMontage function instead"))
    TObjectPtr<UAnimMontage> AnimMontage_DEPRECATED = nullptr;
#endif

In GameplayAbilityRepAnimMontage.h,

#if WITH_EDITORONLY_DATA
	/** AnimMontage ref */
	UPROPERTY(NotReplicated, meta = (DeprecatedProperty, DeprecationMessage = "Use the GetAnimMontage function instead"))
	TObjectPtr<UAnimMontage> AnimMontage_DEPRECATED;
#endif

[Biwei.Lai]

That works fine , thanks a lot

[Sergey_Skyline]

no one checked this in 5.5?
bug tracker?

\edit
anyway my problem turned out to be Unreal Engine Issues and Bug Tracker (UE-214626).
Maybe this will help someone if they encounter a similar problem.

[ND.D.Hip]

Same, I upgrade from UE5.1 to UE5.4. Any solution?

[alphabrox]

5.4.4 still has this bug. Sfak4488’s solution works.
I really hate 5.4

[FailMelon]

If you don’t wanna modify engine code, luckly it is accesible via reflection so just slap this somewhere i just put it on StartupModule.

#if WITH_EDITORONLY_DATA
	auto* rootMotionStruct = FRepRootMotionMontage::StaticStruct();
	auto* brokenProperty = rootMotionStruct->FindPropertyByName(TEXT("AnimMontage"));
	brokenProperty->SetPropertyFlags(brokenProperty->PropertyFlags | EPropertyFlags::CPF_RepSkip);
#endif