Unreal Engine Issues
Unreal Engine Issues
OnSmartLinkReached Event Not Firing in PIE
UE - AI - Sep 20, 2016The OnSmartLinkReached event is not firing in PIE. This is a regression. In 4.12.5 the event fires as expected. Found in 4.13.0 CL 3106830 Reproduced in 4.14 Main CL 3129233. ...
GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues
UE - Simulation - Visual - Aug 30, 2025GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues. The licensee has provided their analysis: We seem to have stumbled acro ...
Foliage instances are not included when exporting a scene to FBX
UE - World Creation - Worldbuilding Tools - Foliage - Aug 4, 2016When exporting Foliage instances to FBX the FBX will not contain any of the foliage instances, but will include any other static or movable geometry. This is a regression. This worked in 4.11.2 but ...
Niagara color picker user parameter preview no longer updates until confirmation
UE - Niagara - Apr 18, 2025Starting with UE 5.4, the Color Picker Tool no longer updates preview values in real time for certain editor windows like Niagara when working with User Parameters. This behavior is a regression fr ...
Key precision problems on some short animations
Tools - Apr 5, 2016Please see attached UE4_anim_interp_bug.fbx for a second example. This works as expected in 4.7 and 4.8 I've got a couple different users reporting this now. I suspected animation compression to ...
Take Recorder - Viewport Freezing and Performance Degradation When Recording Without Subsequences
UE - Virtual Production - Tools - Take Recorder - Apr 11, 2024Description: In Unreal Engine 5.4, when recording camera movements using the Take Recorder with the "Record Sources Into Sub Sequences" option turned off, significant viewport freezing and performan ...
A LevelSequence will lose the binding to objects contained in a level instanced inside another level
UE - World Creation - Worldbuilding Tools - Level Instances - Sep 15, 2025A LevelSequence will lose the binding to objects contained in a level instanced inside another level on 5.6 and up. Refer to the reproduction steps or the shared repro project provided by the licens ...
Cannot export a Datasmith scene to the Unreal Engine project root folder on MacOS.
TM - Interoperability - Oct 29, 2024This is mac specific. I could do the export normally on Windows with the same Twinmotion CL and UE version (5.5 preview). It is also a regression specific to 5.5, since I've been able to export a d ...
[CrashReport] UE4Editor-MetalRHI.dylib!FMetalDeviceContext::CreateDeviceContext()
UE - Graphics Features - Feb 10, 2017Error message: SEGV_MAPERR at 0x3 Source Context: Most recent user affected CL: 3249277 Logs: [Link Removed] [Link Removed] [Link Removed] [Link Removed] CrashReporter User Descriptions:Just i ...
Sequencer - When a subsection has negative play rate, any nested sub-subsections fail to evaluate
UE - Anim - Sequencer - Jul 3, 2025Consider a sequence hierarchy with more than two layers. If the top-level sequence uses a negative timescale on a sub-sequence, the contents inside it animate as expected, but any nested sub-sequenc ...