Unreal Engine Issues
Unreal Engine Issues
Internal Compiler Error: Tried to create a property Crash in scope Beta_C, but another object (ObjectProperty /Game/Alpha.Alpha_C:Crash) already exists there.
UE - Gameplay - Blueprint - Oct 31, 2019After fixing the crash from [Link Removed] when compiling the child blueprint that has claimed the component name the parent was previously using without having compiled the parent, an internal comp ...
FScriptMapHelper::HasKey() and FScriptSetHelper::HasElement() fail on new keys with a substring of another key
UE - Editor - Verse Class Editor - Jan 27, 2022Duplicate key checking in maps and sets in the editor is done via calls to FScriptMapHelper::HasKey() and FScriptSetHelper::HasElement(), but this code is checking for object names which are subsets ...
A Blueprint containing a Macro with a Wild Card input crashes when a Custom Event node has an additional input added
UE - Framework - Blueprint - Aug 16, 2022This is a regression. Tested in //UE4/Release-4.27 CL18319896 In UE4 an error is thrown when attempting to add an input. A Blueprint containing a Macro with a Wild Card input crashes when a Custom ...
The Unreal Engine building dialog either does not appear or is only visible for a brief second
zComponent - Archive - Nov 18, 2022This is not a regression against 5.0. Tested in //UE5/Release-5.0 CL20979098 However, as users have pointed out, this is a departure from UE4. The same process in 4.27.2 demonstrates the building d ...
CopyFileUnderSourceControl Fails on Already Resolved Files
UE - Editor - Apr 12, 2023CopyFileUnderSourceControl has instances when the response is not a success even though the files are copied successfully under source control. It seems FPerforceCopyWorker::Execute() tries to reso ...
Chaos Vehicle does not make them CCD
UE - Runtime - Simulation - Jan 10, 2024AWheeledVehiclePawn class tries to use CCD in the constructor, but Mesh->BodyInstance.bUseCCD = true this code does not work to activate CCD because Physics Assets could not be available at this ...
UDataTableFunctionLibrary::AddDataTableRow() fails for blueprint-defined row structure types
UE - Framework - Blueprint - Feb 2, 2024The editor-scripting blueprint node "Add Data Table Row" fails when the Data Table uses a Row Structure that was defined in blueprint. Internally, it checks if the passed-in UScriptStruct is derived ...
Unable to change Actor Coloration View Modes in PIE
UE - Engine Scaling - Streaming - Jul 20, 2025When in PIE changing Actor Coloration view modes from the viewport visualisation mode [Liit] -> [Actor Coloration] -> ... Does not update correctly when switching view mode and sometimes isn't corr ...
OcclusionFeedback may not be performant for primitives with large screensize
UE - Platform - Mobile - Systems - Dec 13, 2025A licensee reported that the performance could be worse in some scenarios (probably a small scene with large objects) with OcclusionFeedback enabled ( 20fps up if disabled), tested on a Qualcomm 870 ...
Nanite Skeletal Mesh ignores Hidden Material Section flag
UE - Rendering - Features - Nanite - Mar 11, 2026Unlike non-Nanite Skeletal Meshes, Nanite-enabled Skeletal Meshes do not correctly respond to the Show flag passed via ShowMaterialSection(). Consequently, the Isolate checkbox for material slots in ...