Unreal Engine Issues

Pre-UE5 serialized FVariant FVector data corruption when deserialized in UE5

FVariant is a struct that implements a union of data types, including FVector. When assigning an FVariant an FVector value in engine versions UE 4.27 or earlier, the FVariant will deserialize incorr ...

Translucent light grid injection behavior

Light injection into the Translucent Light Grid voxels does not use the correct location for clipping or attenuation. Both of these points are outside the voxel that is being updated. Light attenua ...

Assertion failed after closing project on Oculus Mobile - Referencing AudioMixerSourceManager.cpp:300

This assertion seems to occur when closing the project while a sound is playing on the device. Assertion failed: CommandBuffers[NextIndex].SourceCommandQueue.Num() == 0 [File:D:/P4Workspaces/Switch ...

Windows Game Input - DualSense/DualShock controllers DPad button repeat events behave unexpectedly

[CrashReport] UE4Editor_Engine!FShaderCompilingManager::LaunchWorker() [shadercompiler.cpp:1573]

This is a common and longstanding crash that has occurred since at least 4.9. The issue appears to be due to missing ShaderCompileWorker.exe in binaries, but many of these crashes occur in the vani ...

Morph target is not applied on the first frame in Level Sequence

When a skeletal mesh with morph targets spawns in the sequence, the morph is not reflected in the first frame.  In the ProcessStage_SkinCache call of SkeletalMesh, MorphVertexBuffer->SectionIds is ...

[CrashReport] Crash on Mac related to cooking for IOS

This is a common commandlet crash for Mac users in 4.16. In all cases, the command line is like: "(path/project).uproject" -run=Cook -NoLogTimes -TargetPlatform=IOS -fileopenlog -unversioned -ski ...

[CrashReport] UE4Editor_UnrealEd!SaveWorld() [filehelpers.cpp:359]

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Assertion failed: !bIsReentrant [L ...

GAS: Mixed replication mode and error in MinimalReplicationTags code

We're on 4.25.4. We recently turned on mixed mode replication for GAS, which seems to work fine and reduce bandwidth as expected. However one of our unit tests started failing with this error messag ...

[CrashReport] UE4Editor_UnrealEd!UFbxSceneImportFactory::ImportOneSkeletalMesh() [fbxsceneimportfactory.cpp:2017]

This is a trending crash coming out of the 4.18 release. Users have not provided any descriptions of their actions when the crash occurred. Source Context 2014 USkeletalMesh *ImportedSkelMes ...