Unreal Engine Issues
Unreal Engine Issues
[CrashReport] Crash on Mac related to editor close
UE - Platform - Apple - Jun 6, 2017This is a long-standing Mac crash that occurs with low frequency, but has affected more than 500 users since it started (possibly in the 4.11 release) It has recently been experienced internally by ...
Changing blueprint default values inside arrays only updates loaded child blueprints
UE - Core - Systems - Jul 30, 2020The rules for delta serialization in UE4 are complicated, and the editor tries to hide them from you, which works 90% of the time but can lead to confusion and data loss in other situations. In the ...
Niagara Scalability Crash When Processing Significance
UE - Niagara - Jun 4, 2025Method FNiagaraScalabilityManager::ProcessSignificance() iterates on indices from Context.SignificanceIndices and uses them to access the State and ManagedComponents arrays. It can then decide to cr ...
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 ...
Import Source disappears in Textures after loading asynchronously loaded level
UE - Editor - Content Pipeline - Import and Export - Dec 15, 2015It looks like when reimporting a texture asset into the engine after loading a level, you will be confronted with the File Selection box and not the reimport successful notification. In fact if you ...
Hot Reload does not update blueprint pins
UE - Gameplay - Blueprint - Jan 15, 2015When changing the variable type or return type of a function in code and hot reload in the editor, blueprints that use the variable/function do not have their pins updated until the editor is closed ...
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 ...
Crash Re-Importing animation with Additive Layer Tracks after adding a bone to the hierarchy
OLD - Anim - Feb 13, 2017Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 633] Array index out of bounds: 68 from an array of size 68 Source Context: 733 734 Extrac ...
Classes in TargetDenyList modules are still referenced from Components on BlueprintGeneratedClasses and cause runtime warnings
UE - Core - Systems - Feb 25, 2024Other than the presence of the error and the performance cost of looking for a package on disk that does not exist, there are no behavioral problems. When running with legacy (non-iostore) pakfiles ...