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 ...

Actor in Map in Struct Causes Crash When Changed

UE - Gameplay - Blueprint - Mar 8, 2018

User submitted bug. Editor will crash after changing key or value in Map. ...

Rearranging the position of enumerators in an Enum BP will change references to the enumerators inside Data Tables based on position rather than value

Tools - Nov 12, 2015

Rearranging the position of enumerators in an Enum BP will change references to the enumerators inside Data Tables based on position rather than value. Reproduced in 4.8.3 binary, 4.9.2 binary, 4.1 ...

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 ...

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 ...