Unreal Engine Issues
Unreal Engine Issues
A chaos vehicle that moves at very high speeds with CCD enabled on the vehicle sometimes has a collision response that is abnormal where the vehicle loses a significant amount of speed when colliding with dynamic objects configured as One Way Interaction
UE - Simulation - Gameplay - Dec 16, 2025Context: Continuous Collision Detection (CCD) is being used on a Chaos Vehicle to avoid tunneling issues with certain surfaces as it prevents any missed collisions between fast moving particles and ...
Race condition in full builds of UE4 engine source
UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 26, 2019This is a race condition caused by how "Clean.bat", a batch file used during rebuilds, tries to manually rebuild the UnrealBuildTool project when it runs. This causes a spam of UnrealBuildTool build ...
Culling Distances Not Working For Static Mesh in Procedural Content Generation Tool and Foliage Tool
UE - World Creation - Procedural Tools - Mar 28, 2025When creating Foliage or Procedurally Generated Content the culling settings of the Static Meshes do not apply correctly. As soon as either a minimum or maximum cull distance is set the Static Meshe ...
In editor, sub level instance's streaming state persists incorrectly after toggling Level Behavior without saving
UE - World Creation - Worldbuilding Tools - Level Instances - Jun 11, 2025When adding a sub level with world partition streaming to a main level where the streaming is also enabled, setting* Level Behavior* of the sub level to Standalone, and saving the result, in the fir ...
iOS Shipping Build using std::thread crashes on launch
UE - Platform - Mobile - Jun 2, 2017A user is reporting that using the following code in a GameMode class causes shipping iOS packages to crash on launch:void ANOGSSDKGameModeBase::StartPlay() { std::thread([](){ std::clog << "THRE ...
AddComponent node fails to be scheduled after adding an "expose on spawn" variable to an ActorComponent-based Blueprint Class.
UE - Gameplay - Blueprint - Nov 13, 2015If an existing AddComponent node is placed in an Actor Blueprint's Event Graph for a custom ActorComponent-based Blueprint Class, the node will fail to be scheduled after adding a variable marked "E ...
UGameplayStatics::SpawnEmitterAttached keeps relative location when SnapToTarget is used.
UE - Gameplay - Aug 10, 2016UGameplayStatics::SpawnEmitterAttached will keep relative position when using SnapToTarget. ...
Create Session does not work in a packaged game from any project that has used C++
UE - Networking - Dec 28, 2015After adding C++ to a content-only project, Create Session no longer works in a packaged game. The following warning appears in the log: LogScript:Warning: CreateSession - Invalid or uninitialized ...
Changing transform of simulated component during physics freezes motion
UE - Simulation - Physics - Oct 13, 2016If something is executed before a SetActorRotation node on Tick inside of a SceneComponent class BP and then added to an Actor class BP, the physics will lag User Description: When using set rotat ...
[CrashReport] UE4Editor_Engine!FAnimNotifyEvent::IsBranchingPoint() [animtypes.cpp:86]
OLD - Anim - Aug 29, 2017This is a common crash occurring in the 4.17 release. Users have not provided any descriptions of their actions when the crash occurred. Source Context 72 float FAnimNotifyEvent::GetDurati ...