FUniqueNetIdRepl::NetSerialize() crashes when embedded in a TArray() of structs.

Networking - Jun 29, 2020

Calling the NetSerialize() function of FUniqueNetIdRepl from a custom NetSerialize() causes a crash. This only seems to occur when the struct is part of an array RPC parameter. ...

PIE Dedicated Servers Have Lower Saturation Limits

Networking - Jun 16, 2020

UNetConnection::Tick() clamps the delta time used for the bandwidth limit to the desired tick rate (1 / DesiredTickRate). In PIE, this number is different than the net server max tick rate, so the b ...

Blueprint properties of replicated subobjects don't replicate by default

Networking - May 18, 2020

The base implementation of UObject::GetLifetimeReplicatedProperties doesn't check to see if its class is a blueprint-generated class and add its properties, like UActorComponent::GetLifetimeReplicat ...

Cannot access private member MarkPropertyDirtyFromRepIndex error when building a nativized blueprint with a replicated property

Networking - May 14, 2020

The following error occurs when building a project that has a replicated variable with the replication condition set to Skip Owner inside a nativized blueprint.UATHelper: Packaging (Windows (64-bit) ...

IsReplicationPausedForConnection is never called

Networking - Apr 20, 2020

AActor.IsReplicationPausedForConnection is never called. ...

GitHub 6722 : Demo Replay Scrubbing Fix For RootComponent Mobility

Networking - Feb 25, 2020

See https://github.com/EpicGames/UnrealEngine/pull/6722 (shelved in CL 11616092) DemoNetDriver's scrubbing fails to properly set mobility of components on an Actor in certain cases. Create a proj ...

PIE crash due to non-empty ULevel::DestroyedReplicatedStaticActors array

Networking - Feb 17, 2020

It's possible to end up in a state where some entries were saved in ULevel::DestroyedReplicatedStaticActors, which causes a crash when PIE starts up. I'm not sure how entries could end up in this l ...

Using ServerTravel <MapName> command with Seamless travel causes level blueprint logic to not run on client

Networking - Jan 14, 2020

When calling the ServerTravel command when using seamless travel, level blueprint logic is not being run on the client side.  NOTE: Adding a small delay (tested with .2 to 2 seconds) after the "B ...

It may be possible to send an actor RPC before successful replication of the actor

Networking - Nov 27, 2019

It was reported on UDN that it's possible to receive an RPC for an actor before the actor itself has replicated. The net driver tries to prevent this possibility by calling ReplicateActor in UNetDri ...

Calling GEngine->Browse from an RPC implementation causes a crash

Networking - Nov 5, 2019

The engine is not resilient to calling Browse from within an RPC implementation, and likely not resilient to other ways of destroying the net driver within RPCs/OnReps. It's not something we need to ...