Visual Studio builds currently fail when a project includes a UFUNCTION with Server, Reliable, and WithValidation specifiers (with appropriate definitions in the source file).

UE - Networking - Apr 1, 2015

Using UFUNCTION(Server, Reliable, WithValidation) with an RPC function results in a failed build in Visual Studio. The same test in Main yields a different set of error messages. ...

Crash when travelling during ability activation when URL contains "#"

UE - Framework - Jul 18, 2025

This issue is related to [Link Removed], where the "?listen" option sent on the URL to clients could cause issues with RPCs being called locally during travel. The fix to remove the "?listen" option ...

Ribbon Particle Normals are reversed from default Sprite Particles

UE - Graphics Features - Oct 13, 2015

It appears that the Vertex Normals from Ribbon Particles are opposite of what is expected via the Default Particle System given both systems share the same alignment (Facing Camera) [Image Removed] ...

CppCompileWarningSettings.NonInlinedGenCppWarningLevel messages should contain Warning\Error

UE - Foundation - Cpp Tools - UnrealBuildTool - Oct 8, 2025

The messages emitted when CppCompileWarningSettings.NonInlinedGenCppWarningLevel is set to Warning\Error should contain the literal so the tools pick them up and react accordingly. From the EPS c ...

Cumulative Patching does not work with Pak signing

UE - Foundation - Feb 20, 2024

Cumulative patching is implemented by copying the generated pak files during staging of the base and each patch to the Releases directory. When creating a patch, all of the pak files from the releas ...

SceneTexture:WorldNormal causes decal to ignore Emissive Color

UE - Rendering Architecture - Materials - Mar 11, 2022

SceneTexture:WorldNormal causes decal to ignore Emissive Color.  ...

Crash on project open

UE - Gameplay - Blueprint - Feb 5, 2015

EDIT: CrashReporter link: [Link Removed] EDIT2: Likely also this crash: [Link Removed] EDIT3: This crash appears under a different Bugg in 4.7: [Link Removed] Engine crashed when attempting to op ...

Event Dispatcher implementation called several times (number of bound refs increases every compile)

UE - Gameplay - Jun 26, 2018

The number of calls to the Event Dispatcher increase each time the blueprint actor containing the reference is compiled. This issue was not present in 4.18.3 (CL-3832480) but is in 4.19.2 (CL-403378 ...

Hot Reload Crash involving variables in USTRUCTs

UE - Foundation - Cpp Tools - Hot Reload - Sep 1, 2016

This issue was created for this UDN post: https://udn.unrealengine.com/questions/306933/hotreload-crashbad-behavior-when-addingremoving-pa.html This repro is based off his last repro, cutting it do ...