Event Dispatcher not being called in 4.6

UE - Gameplay - Blueprint - Dec 8, 2014

ED nodes in 4.6 but are not being executed in standalone or cooked games. Also, users receive compile errors when the project is saved and reopened that resolve when the blueprint is recompiled. ...

Pre-UE5 serialized FVariant FVector data corruption when deserialized in UE5

UE - Framework - LWC - Jan 15, 2024

FVariant is a struct that implements a union of data types, including FVector. When assigning an FVariant an FVector value in engine versions UE 4.27 or earlier, the FVariant will deserialize incorr ...

Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key causes a memory leak

UE - Framework - Blueprint - Apr 15, 2025

When Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key, the function construct the default structure in-place on the given pointer without destroying the object. This behavior ca ...

[AI] Debug Render Scene Proxy hits ensure for registering a delegate twice during level streaming.

UE - AI - Debugging - Aug 31, 2022

Description from licensee: We're seeing an ensure get tripped up in FDebugRenderSceneProxy that says "DrawDelegate is already Registered!". Debugging the issue, we have confirmed that the DrawDeleg ...

Launching Android project to device results in Assertion Failed: AsyncLoading.cpp, Line 3710

UE - Platform - Mobile - Aug 31, 2020

After updating to 4.25.1 from 4.25 Packaged Android game crashes constantly with objects added to the map 4.25 Packaged game did not crash (editor did a lot but glad thats fixed in 4.25.1) Empty map ...

[CrashReport] Assertion failed: !PinRef->bWasTrashed | UEdGraphPin::SerializePin()

UE - Gameplay - Blueprint - Aug 29, 2017

This is a common and longstanding crash that has occurred since at least 4.15 and affected nearly 500 users. The CrashGroup was previously linked to [Link Removed], but that had specific repro step ...

Unable to open UE4Editor on Linux - Bad hlslcc header found

UE - Platform - Linux - Nov 4, 2015

UE4Editor does not open on Ubuntu 15.10 due to the following error: [2015.11.04-16.19.35:974][ 0]LogOpenGLShaderCompiler:Error: Bad hlslcc header found! Missing '#'!Error in `./UE4Editor': free(): ...

[CrashReport] UE4Editor_Renderer!FUniformMeshConverter::Convert()

UE - Graphics Features - Aug 3, 2017

This is a regular crash that has occurred through 4.16 and into the 4.17 previews. The callstack is similar to [Link Removed] (invalid), although the error message is different. User Description ...

Crash when resizing window using Quad Stereo Buffer

UE - Virtual Production - nDisplay - Oct 2, 2019

We noticed crashes in our application when we attempted to resize a window or switch to full-screen mode. Hence, resizing windows and switching to full screen will result in a crash on Unreal Engine ...

Crash on Mac on exit.

Media Framework - Aug 17, 2020

A licensee reported trouble with a crash on exit on Mac. They discovered that the file AvfMediaPlayer.cpp, on the function Open there is this piece of code:// Force the AV player to not be able to ...