Unreal Engine Issues
Unreal Engine Issues
Cook Non-Determinism in USplineComponent
UE - Editor - Feb 25, 20261. Non-Deterministic LastAuthority Serialization LastAuthority is assigned in USplineComponent::Serialize. Its value depends on the order in which the object and its archetype are serialized, leadi ...
Crash when using "Convert to Variable Curve"
OLD - Anim - Jun 7, 2016Error message: Access violation - code c0000005 (first/second chance not available) Source Context: 7 8 DECLARE_CYCLE_STAT(TEXT("AnimSeq EvalCurveData"), STAT_AnimSeq_EvalCurv ...
Crash when importing material assigned to FBX with illegal characters through the Full Scene Importer
UE - Editor - Content Pipeline - Import and Export - Jun 21, 2016If you have an illegal character (/ or ?) in your material name embedded with your FBX the editor will crash when using the new Full scene importer and selecting the Materials Tab. Tested in and ...
Large Landscapes cause long PIE start time delays
UE - LD & Modeling - Terrain - Landscape - Jan 29, 2020These delays appear with large Landscapes (for example 8029 x 8029) . The delays only start occurring after the level is saved and reopened. After which PIE start times will be 5 to 15 times longer ...
Breakpoint on SetText node in WBP PreConstruct triggers editor hang on save
UE - Gameplay - Blueprint - Apr 17, 2024A user reported that when calling SetText on a text widget in a widget blueprint's PreConstruct causes an editor hang when you put a breakpoint on SetText and attempt to save the asset. The issue i ...
Functional Test won't start when placing a moving actor inside the level if setting Navigation Mesh's Runtime Generation to Dynamic
UE - Automation Test - Mar 21, 2019User is trying to use the Functional Test class to construct some automated test cases. Whilst doing this they noticed that adding a BP_Actor (just a static mesh engine cube) that simply rotates (v ...
[CrashReport] UE4Editor_Foliage!operator<<() [foliageinstancebase.cpp:93]
UE - World Creation - Worldbuilding Tools - Foliage - Jul 5, 2016This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Fatal error: [Link Removed] [Line: ...
[CrashReport] UE4Editor_CoreUObject!UObjectProperty::SerializeItem() [propertyobject.cpp:39]
UE - Gameplay - Blueprint - Apr 19, 2016This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Access violation - code c0000005 ( ...
When using Perforce, saving a level over another leaves the target umap file as "marked for delete"
UE - Editor - Mar 11, 2025When working on a level asset and using command "File – Save Current Level As..." to save it over a different level asset, the engine first deletes the target level (that's going to be overwritten) ...
Wrong density calculation in UBodySetup::CalculateMass
UE - Simulation - Core - Sep 29, 2025Wrong density calculation in UBodySetup::CalculateMass. The licensee has provided the following analysis and suggested fix: In UBodySetup::CalculateMass, the following code is present: // physical ...