Actor Channel failure occurs when quickly unloading and loading a streaming level

UE - Networking - May 8, 2025

With high enough latency, quickly unloading an reloading a streaming level with a replicated actor on the server can cause the actor channel on the client to fail to find this actor: UActorChannel:: ...

Assertion failed in FNetGUIDCache::CleanReferences during seamless travel after reloading primary asset package

UE - Networking - May 7, 2025

Following this sequence of events, the ObjectLookup and NetGUIDLookup on the server's PackageMapClient will end up in a bad state. In the ObjectLookup Map, the primary asset's package will be mapped ...

Fatal error when creating listen server on an instance with a PendingNetGame

UE - Networking - Apr 28, 2025

This seems to occur because the PendingNetGame is not destroyed when the instance browses to the new level to start listening. In UEngine::LoadMap, UWorld::SetGameMode will create the game mode, pro ...

FFastArraySerializer::DeltaFlags may be saved to blueprint CDO, causing delta struct serialization to be skipped

UE - Networking - Mar 28, 2025

When an actor's replicator is first created and initialized, FObjectReplicator::InitWithObject will use the archetype as the source object for copying the properties. From there, the custom delta pr ...

COND_InitialOnly property not written to first replay checkpoint after being changed

UE - Networking - Feb 5, 2025

When recording a checkpoint, it is treated as an initial replication, as all the changed properties since the channel was opened need to be recorded. This normally results in any initial only proper ...

Check hit when setting push-model array from a different actor's blueprint

UE - Networking - Jan 31, 2025

This is due to the same reason behind [Link Removed], as the stack object is passed to MARK_PROPERTY_DIRTY rather than the array property's owner.  ...

UEditorEngine::AddPendingLateJoinClient checks original PIE/SIE state, not current state

UE - Networking - Jan 27, 2025

When adding late joining clients, the engine checks the originally requested EPlaySessionWorldType, rather than checking whether or not the session is currently simulating or not. This means if the ...

NetUpdateFrequency Affected by Global Time Dilation

UE - Networking - Jan 13, 2025

Changing the global time dilation in a multiplayer game affects the rate at which actors are considered for replication, and setting it to 0 will even cause replication to stop entirely (unless the ...

Ejecting from player in multiplayer PIE results in the wrong world being displayed

UE - Networking - Dec 13, 2024

In [Link Removed], it mentions that only the instance in the editor viewport supports switching to Simulate In Editor when running multiple instances in PIE. However, rather than showing that instan ...

No warning given when a subobject is registered to a component not using the registered subobjects list

UE - Networking - Nov 15, 2024

AActor::AddReplicatedSubObject will ensure in this case if the actor doesn't set bReplicateUsingRegisteredSubObjectList, but there is no equivalent check in AActor::AddActorComponentReplicatedSubObj ...