Compiler error after changing the class in a Spawn Actor from Class node, undoing with Ctrl + Z, refreshing the node, and reconnecting exposed variables

UE - Gameplay - Blueprint - May 26, 2015

Compiler error after changing the class in a Spawn Actor from Class node, undoing with Ctrl + Z, refreshing the node, and reconnecting exposed variables. "Error Internal compiler error inside Creat ...

Drag and Drop fails in Standalone and Packaged builds when WidgetComponent’s Widget is set at runtime

UE - Editor - UI Systems - Dec 4, 2025

When a UWidgetComponent has its widget assigned dynamically at runtime using CreateWidget and SetWidget, drag & drop operations fail in Standalone Game and packaged/game builds, while working correc ...

Attempting to use the GameplayTags module in a binary code project will result in build failures in Visual Studio.

UE - Foundation - Core - Mar 27, 2015

Using the GameplayTags module in a code project created with the binary version of the Engine results in a build failure in Visual Studio. The following error is shown: 1> D:/Epic Games/4.7/Engine ...

Editor Crashes when placing a widget blueprint from one widget blueprint into another via the user created section

UE - Editor - UI Systems - Oct 8, 2014

CHANGELIST: 4.5.0-2316912 CRASHREPORT: Did not produce an error report CALLSTACK: Did not produce an error report DESCRIPTION:   Editor Crashes when placing a widget blueprint from one widget b ...

[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 ...

Failed to generate Nanite data for mesh with bDoFastBuild enabled

UE - Graphics Features - Nanite - Oct 1, 2025

If "bDoFastBuild" is enabled on a Static Mesh asset, in-editor it will never be able to have Nanite data built for it, preventing the Static Mesh from using Nanite. There is no way to fix this issu ...

BP: DEBUG: Debug filter automatically switches to one of the instances of blueprint which doesn t let user debug other instances of blueprint

UE - Gameplay - Blueprint - Aug 5, 2014

GameVersion Branch: UE4 Configuration: Main Version: 2242091 CommandLine:qagame -log Label: GUBP Node Shared_LabelPromotable built from changelist 2242091 DESCRIPTION: Debug filter automatically sw ...

[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 ...

Player Character does not collide with landscape

UE - LD & Modeling - Terrain - Landscape - Mar 8, 2015

UPDATE: 3/9/2015 Additional Information: User on thread https://answers.unrealengine.com/questions/186928/landscape-collison-issues-recreatelandscapecollisi.html reported workaround did not fix e ...