t.MaxFPS 0 locks FPS to 120 instead of unlocking it in Viewport

Tools - Nov 7, 2017

When unlocking FPS in Viewport it defaults to 120 instead of potential max FPS. If you do this during Launch the 't.MaxFPS 0' or 't.MaxFPS -1' commands unlock the FPS to the max the GPU allows in th ...

ensure(PinHelpers::UnresolvedPins.Num() == 0); fails after undoing in the editor

UE - Framework - Blueprint Editor - Sep 6, 2025

The underlying cause is some edge case involving a math expression node, which does some perhaps naive things with a contained graph. ...

[CrashReport] UE4Editor_Engine!FSkeletalMeshObject::UpdateMinDesiredLODLevel() [skeletalrender.cpp:81]

OLD - Anim - Nov 2, 2017

This is a somewhat common crash that has occurred since at least the 4.16 release. User DescriptionsReimported a skeletal mesh from an FBX file.reimported static mesh Source Context 70 v ...

Crash after setting a key on a Rotation Track, then trying to right click the key with Transform track collapsed

UE - Anim - Sequencer - Aug 3, 2016

Error message: Access violation - code c0000005 (first/second chance not available) Source Context: 336 337 if (bHasRotationKeys) 338 { 339 TSharedRef<FStru ...

Modified a mesh used as complex collision mesh does not affect the collision in the editor

UE - Editor - Feb 17, 2020

When a user changes any properties (for calling PostEditChangeProperty ) in parent static mesh or restarting the editor, the modified mesh is applied correctly. how to reproduce: [Link Removed] ...

Skeletal mesh LOD 0 "LOD Info" loose their settings when we reimport

UE - Editor - Content Pipeline - Import and Export - Mar 6, 2020

Set critical because loosing settings is dangerous. This is not a regression, the bug is in 4.22 and earlier version. We have to save all options of the LODInfo, currently nothing is saved. Also sh ...

[CrashReport] UE4Editor_LandscapeEditor!FLandscapeEditorCustomNodeBuilder_TargetLayers::HandleAcceptDrop()

UE - LD & Modeling - Terrain - Landscape - Jul 6, 2017

This is a common crash affecting users in 4.16.2. It is similar to [Link Removed], which was potentially fixed in 4.16.2. Users have not provided any additional information. Source Context 803 ...

Getting Emitter.NumParticles on Niagara's GPU compute sim returns 0

UE - Niagara - Jul 27, 2023

This problem looks like the following parameters are not defined correctly. The correct parameter is Engine_Emitter_NumParticles. Engine_Emitter_NumParticles and PREV_Engine_Emitter_NumParticles .\ ...

SkyLight Leaking does not affect reflections when the SkyLight is static but static lighting is disallowed

UE - Rendering - Graphics Features - Sep 10, 2025

Reflections do not receive SkyLight leakage contribution from a static SkyLight when static lighting is disallowed. This is caused by the function UpdateSkyIrradianceGpuBuffer checking if the SkyLig ...