Crash reimporting an FBX with LODs and Morph Targets, but leaving "Import LODs" disabled

UE - Editor - Content Pipeline - Import and Export - Jan 4, 2017

Error message: Assertion failed: ImportedResource->LODModels.IsValidIndex(LODIndex) [Link Removed] [Line: 282] Source Context: 270 * Constructor. 271 * Converts a skeletal mesh to ...

Available network bandwidth is too low for uncapped but slow frame rates

UE - Networking - Sep 24, 2020

The networking system has a max frame rate of 120hz by default. Inside UNetConnection::Tick it computes an estimated bandwidth by using that max frame rate, the engine's max frame rate, and the actu ...

In Standalone mode, when reading world partition actor descriptors for BP actors, "bIsSpatiallyLoaded" receives its value from the native base class instead of the BP class, so BP actors are loaded/unloaded based on the wrong condition.

UE - World Creation - Worldbuilding Tools - World Partition - Oct 15, 2024

Consider an actor defined in C++ with "bIsSpatiallyLoaded" set to true (the default), and a derived blueprint that overrides "bIsSpatiallyLoaded" to false. Now consider an actor instance of that blu ...

[CrashReport] Crash When Undoing Changes in Widget Blueprints

Tools - Oct 13, 2016

This 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 ( ...

[CrashReport] UE4Editor_Core!FModuleManager::LoadModuleChecked() [modulemanager.cpp:350]

UE - Foundation - Core - Aug 10, 2017

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Assertion failed: Module [Link Rem ...

Surface snapping attached actors cause unexpected behavior

Tools - May 17, 2019

Surface snapping causes erratic changes in scale to StaticMeshActors that have children of the same type. The user also has provided a potential solution to this bug (Please see the code below. N ...

In Sequencer, copying a Missing/Invalid Bound Object to a track may crash the Editor with an Unhandled Exception at UExporter::FindExporter()

UE - Anim - Sequencer - Jun 26, 2025

In Sequencer, copying a Missing/Invalid Bound Object to a track may crash the Editor with an Unhandled Exception at UExporter::FindExporter(). The licensee has provided a txt file that contains the ...

A build may fail in Visual Studio if a space is added after the # in an include pre-processor instruction to allow a struct in one header file to reference a struct in the other

UE - Foundation - Core - Sep 23, 2016

A project building in Visual Studio will sometimes fail with the error Unrecognized type 'FBar' - type must be a UCLASS, USTRUCT or UENUM. This can occur in situations where one struct was reference ...

Hot Reload crash on PIE with custom AIController and Perception Component

UE - AI - Sep 29, 2015

If a pawn in the level is using a custom AI Controller that sets the AIPerceptionComponent in code, the editor will crash on PIE after a hot reload. CrashReporter: [Link Removed] ...

Crash in FNetGUIDCache::GetObjectFromNetGUID()

UE - Networking - Jun 28, 2016

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Assertion failed: Package->IsFullyLoaded() [Link Removed] [Line: 2296] Source ...