Unreal Engine Issues

Blueprint fails to compile when adding new member to struct that is an input parameter of implemented interface function

Adding variables to a structure that is an input parameter of an interface function causes a compile error in any blueprint that implements the interface until the interface is recompiled. Compile ...

Crash when manipulating Bone Space IK before setting EffectorSpaceBoneName

Error message: Assertion failed: Pose.IsValidIndex(BoneIndex) [Link Removed] [Line: 528] Source Context: 513 const FTransform& ParentTransform = GetComponentSpaceTransform(ParentIndex); ...

Translucent materials in the PostMotionBlur pass can cause a flickering viewport artefact when using TAA

There appears to be a bug relating to rendering multiple windows that can trigger under unknown circumstances. It has been reported on rectangle lights in the forums and on PostMotionBlur materials ...

Linked animation graph doesn't trigger anim notifications on dedicated server.

Linked animation graph doesn't trigger anim notifications on dedicated server. There is no expected message in log: LogBlueprintUserMessages: [HitReact_AnimBP_C_0] Client 0: HitNotify IsServer: tru ...

Properties not serialized when moving actor/component depending on unrelated specifiers

When an actor is moved on the level editor viewport, it is reconstructed along with its components, which at first makes their properties reset to their default state. Thankfully, this does not happ ...

When using Subversion (SVN) and Lock's comment is Japanese outside SourceControl, parsing of xml fails and Status may become NotControlled.

If user lock assets with Japanese comments outside source control, XML acquired in svn status may contain Japanese strings, and XML parsing may fail and become NotControlled. This issue does not oc ...

Editor crashes when replacing Packed Level Actor assets during asset deletion process

Maximum number of State Machine connections?

Adding more than 8 connections to or from a state in the state machine results in unpredictable behavior, like causing an animation to fail. (See image.) Was able to reproduce with user's test file ...

[CrashReport] Crash on Mac during cook - UEditorEngine::UpdateAutoLoadProject()

This is a top crash on Mac. This crash has only occurred on the 4.16.1 release (there are no records of it in 4.16.0). Repro steps are currently unknown, but the crash occurs in Commandlet mode and ...

[CrashReport] UE4Editor_CoreUObject!FScriptArrayHelper::EmptyAndAddUninitializedValues() [unrealtype.h:2703]

This is a trending crash coming out of the 4.17.0 release. Based on user descriptions, this crash occurs on Play or Compile for affected users. User DescriptionsAgain crashing when I hit playIF I C ...