Unreal Engine Issues
Unreal Engine Issues
Python commandlet crashes when spawning actors in a level
UE - Editor - Workflow Systems - May 7, 2019Using the python commandlet to spawn actors within a Map and then saving it causes a crash in the commandline. Tested in 4.21.2 (CL - 4753647), 4.22.1 (CL - 6063286), 4.23 (CL - 6338849) ...
FNiagaraScalabilityManager incorrectly reactivates a NiagaraComponent that was deactivated by runtime user code
UE - Niagara - Scalability - Oct 1, 2025Context: The Niagara System is the primary tool to do visual effects inside Unreal. Niagara systems can be culled due to distance. Problem: Once a deactivated Niagara System is culled due to distan ...
Assertion trying to open packaged project on Linux: Default__MaterialInterface was listed as a fixed load order but was already processed
UE - Foundation - Core - Feb 20, 2017This might be related to [Link Removed]. ...
Startup Movie renders as a black screen on some Android devices
UE - Platform - Mobile - Jun 29, 2018While testing on the 10661_Xiaomi Mi 5C the Startup Movie would occassionally render as a completely black screen while still playing the audio from the Startup Movie sample. This was the most consi ...
Interpolators of Particle Dynamic Parameters Need "nointerpolation".
UE - Niagara - Aug 1, 2019Regardless Niagara or Cascade, dynamic parameters for particles are passed to pixel shaders from vertex shaders via InterpolantsVSToPS. It can cause a precision error on some materials, for example ...
[CrashReport] UE4Editor_UnrealEd!FComponentEditorUtils::DeleteComponents() [componenteditorutils.cpp:539]
UE - Gameplay - Components - Dec 1, 2017This is a common crash in the 4.18 release. Users have not provided any descriptions of their actions when the crash occurred. Source Context 524 OutComponentToSelect = RootComponent; ...
Max Depenetration Velocity cannot be set to zero after setting it to a non-zero value
UE - Simulation - Core - Mar 1, 2021It seems that when setting the Max Depenetration Velocity to a non-zero value, you are then unable to set it back to 0. Tested in //UE4/Release-4.25 @ CL 14469661 and this did not occur so marking ...
Infinite Loop When Generating HLOD Clusters
UE - World Creation - Worldbuilding Tools - HLOD - Aug 8, 2018The HLOD system gets stuck in a infinite loop when building. Comment from the user: ++I've tracked it down to this code: const AActor* UHLODProxy::FindFirstActor(const ALODActor* LODActor) { a ...
[CrashReport] UE4Editor_Engine!FColorVertexBuffer::GetVertexColors() [colorvertexbuffer.cpp:313]
Tools - Nov 21, 2017This is a common crash in the 4.18 release. Users have not provided any descriptions about their actions when the crash occurred. Source Context 301 /** 302 * Specialized assignme ...
[CrashReport] UE4Editor_UMG!TBaseDelegate<FMargin>::operator=() [delegatesignatureimpl.inl:381]
UE - Editor - UI Systems - Aug 29, 2017This is a longstanding and common UMG crash that has affected more than 200 users since at least the 4.15 release. User DescriptionsI was working in the UI and undid several last changes in quick s ...