Unreal Engine Issues
Unreal Engine Issues
Strange intermittent CCD behavior on constrained physics bodies
UE - Simulation - Physics - Oct 23, 2019There is some strange issue with CCD where constrained CCD objects can get velocity nulled when hitting things while constrained, its very hard to reproduce normally in engine but happens often in V ...
Crash when quick binding a function in a class that extends LevelSequenceDirector
UE - Anim - Sequencer - Sep 16, 2020The purpose was to create a Level Sequence Director inheritance class so that the same event could be reused in multiple sequencers. Attempting to quick-bind this base Level Sequence Director event ...
Python crash the engine at exit.
UE - Editor - Workflow Systems - Oct 25, 2022A UDN reported various crashes at exit in the embedded Python library. I was able to repro the issue in Release-5.1 and trace it back at the point where python runs its garbage collection in Py_Fina ...
GAS and single process PIE: modifiable static variables accessed by server and client
UE - Gameplay - Gameplay Ability System - Nov 16, 2022See: UAbilitySystemGlobals::HandlePreLoadMap GAS features static variables that are modified by both server and client, thus result in issues in single process PIE where they access the same memory ...
When duplicating the last point in a closed-loop spline, its metadata is inserted at the wrong index
UE - Editor - Workflow Systems - Nov 1, 2023The SplineComponentVisualizer allows users to alt+drag on a spline point to duplicate it. When this is done on the last point of a spline marked as "closed-loop", the new point is correctly added at ...
Blueprint CDO contains removed component from parent class
UE - Gameplay - Blueprint - Apr 28, 2015Blueprint CDO contains removed component from parent class. From the AnswerHub post: "It appears that if a component is removed from the C++ class, the CDOs for all of the blueprints remain unchang ...
[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 ...
Simulated ability tasks not being cleaned up in UActorChannel::ReplicationMap
UE - Networking - Nov 20, 2018I've noticed the issue occurring in both 4.20.3 (CL 4369336) and 4.21.0 (CL 4541578). The user on AnswerHub has also noticed the issue in 4.20.2 (CL unknown) and claims the issue did not occur in 4. ...
Crash when starting PIE on a World Partition level with a Niagara Component inside nested Child Actor Components
UE - Niagara - Jun 25, 2024Consider an actor containing a Niagara Particle System Component, which is instantiated from another actor's Child Actor Component. When initializing PIE on a World Partition level containing this s ...
Wrong calculation of "MaxAllocatedCountEstimate" inside FNiagaraRendererRibbons::GenerateDynamicData()
UE - Niagara - Mar 20, 2026Starting with UE 5.4, function FNiagaraRendererRibbons::GenerateDynamicData() from file [NiagaraRendererRibbons.cpp] attempts to calculate DynamicData->MaxAllocatedCountEstimate as such: DynamicDat ...