Unreal Engine Issues

Crash when playing NiagaraSystem with mesh renderer in CPUSim with Compress Attributes enabled when stompmalloc is enabled

Crashes when playing Niagara particles with the following conditions enabled. It crashes only when stompmalloc is enabled, not when disabled. Enable Ray tracingEnable Compress Attributes in System P ...

Different CRC32 Results for Repeated Hashing of UStaticMesh

1. Download the Licensee repro, compile, and open:https://udn.unrealengine.com/s/contentdocument/069QP00000CdN7WYAV 2. Press the first hatched button on the top bar, next to the Platforms dropdown. ...

Custom node not working with material attributes

Using Material Attributes as an input to a Custom Expression causes the HLSL Translator to create multiple CustomExpression# functions, for each used member of the Material Attributes, rather than u ...

crash at checkUERenderCommandPipeIsReplaying in RenderScenecpp

Drawing a material to a render target when that material samples an RVT can cause an editor crash. In our testing, the check() did not always occur on the first PIE session, but would always occur ...

Compilation errors with UE_NET_ENABLE_REPLICATIONREADER_LOG enabled

Enabling UE_NET_ENABLE_REPLICATIONREADER_LOG results in the following errors: {{4>[1/5] Compile [x64] ReplicationReader.cpp 4>D:\P4V\UE5-Main\Engine\Source\Runtime\Experimental\Iris\Core\Private\Ir ...

Material ParticleRandom node doesn't have proper value returned in specific case

Flickering shadows/GI when DrawMaterialToRenderTarget is called per tick in PIE

When DrawMaterialToRenderTarget function is called on tick and actors are spawned in game, the lumen shadow/GI visually flickers. Debugging shows that the lumen screen probes are flickering as well. ...

Integer overflow in NaniteBuilder can lead to an editor crash on certain meshes

NaniteBuilder uses an int8 type for ExternalEdges and counts adjacency with a int32. The bug stems for the cast to int8 when adding the adjacency count into the ExternalEdges array. The precision l ...

PCG Graph callback fails after compiling blueprint

PCG graph callbacks in BP do not appear to get called correctly after the blueprint is compiled. ...

Using Custom Primitive Data as Final Colour in a UI Material crashes the engine with a missing uniform buffer

Using custom primitive data as an input in a UI material causes the engine to crash in the RHI thread. The exact crash is "Missing uniform buffer at slot 1, stage SF_Pixel." at Engine\Source\Runtime ...