Unreal Engine Issues
Unreal Engine Issues
Assertion failed: (Index >= 0) & (Index < ArrayNum) when importing large Alembic file
UE - Editor - Content Pipeline - Datasmith - Importer - May 3, 2022Regression testing done on //UE4/Release-4.27.2 CL-18427296 and this issue did occur. [Link Removed] [Link Removed] Below is snips of customers description and proposed workaround:Importing alembi ...
Users Unable to create C++ Projects
UE - Foundation - Core - Mar 6, 20152nd AH post with the same issue: https://answers.unrealengine.com/questions/183441/cant-load-c-projects.html Multiple people have reported not being able to create a C++ project. Creating a Bluepr ...
[UDN - 00707230] DetailLayoutHelpers ensure when using VisibleAnywhere Instanced properties
UE - Editor - Workflow Systems - Jan 11, 2024From UDN Description Hello, there's an ensure that's firing in `DetailLayoutHelpers.cpp#137`: [Start code block] ensure(PropertyNodeMap.ParentProperty == CurObjectNode); [End code block]when ...
StateTree: While editing State Parameters or exposed properties of a Condition/Task, an ensure() fires when editing inputs of a Property Function bound to an array element
UE - AI - StateTree - Mar 5, 2026Consider an array property that can be edited in the StateTree editor. This can be a State Parameter or an exposed property of a Condition or Task, for example. Each element of the array can be boun ...
Wrong WPO motion vectors due to Periodic World Space node
UE - Rendering - Graphics Features - May 13, 2026We've noticed smearing in grass due to wrong motion vectors. This appears to be caused by lack of previous frame support in the periodic world space node. This is how we fixed it: In MaterialTempl ...
[CrashReport] Crash on Mac related to editor close
UE - Platform - Apple - Jun 6, 2017This is a long-standing Mac crash that occurs with low frequency, but has affected more than 500 users since it started (possibly in the 4.11 release) It has recently been experienced internally by ...
POST /v1/testdata API doesn't properly convert data to BSON
UE - Foundation - Horde - Server - Jun 24, 2025Post: { "jobId": "685b12ad6765a5c9fefad260", "stepId": "a991", "key": "output-otem-job2", "data": { "Type": "Simple Report", "TestName": "EditorClientBoot", "Descript ...
Event Tick is not running once packaged
UE - Gameplay - Components - Jul 20, 2015Event Tick works when it's running on Windows however once it's packaged or even launched onto all platforms, the event tick does not work as anticipated. This happens on all platforms. *Project ca ...
[CrashReport] UE4Editor_Engine!LoadSpecialMaterial() [unrealengine.cpp:1523]
UE - Graphics Features - Nov 10, 2017This is a longstanding crash that has occurred for more than 200 users since at least 4.13. Based on user descriptions this appears to permanently corrupt a project. User DescriptionsI just turned ...
[CrashReport] UE4Editor_Slate!FMenuStack::DismissInternal() [menustack.cpp:582]
UE - Editor - UI Systems - Slate - Apr 15, 2016Error Message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 785] Array index out of bounds: 1 from an array of size 0 Source Context: 567 } 568 } 569 ...