Actors disappearing after saving a large number of modifications to world partition maps

UE - Editor - Workflow Systems - Nov 4, 2022

From Licensee: "We've encountered a world partition bug where newly created actors go missing in the viewport and Outliner after saving modifications to a large number of actors. This bug is partic ...

Actor Class Reference can take invalid Value, can lead to crash

UE - Gameplay - Blueprint - Oct 4, 2017

REGRESSION: Can be certain as this testing was blocked by [Link Removed] Through a specific chain of events (see repro), it's possible to have a non-actor as the value for an Actor Class Reference, ...

[CrashReport] UE4Editor_Engine!operator new<FBatchedLine,FDefaultAllocator>() [array.h:2812]

OLD - Anim - Jun 2, 2016

Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 804] Array index out of bounds: 175 from an array of size 171 Source Context: 2797 2798 temp ...

Crash when editing Gameplay Effect containing a deleted/renamed Gameplay Attribute

UE - Gameplay - Gameplay Ability System - Mar 9, 2025

When modifying the name of a gameplay attribute that is used with a modifier on a gameplay effect, attempting to remove/change the modifier causes an editor crash. This appears to be due to line 29 ...

This Blueprint will not compile and causes a crash in 4.8

UE - Simulation - Physics - Mar 18, 2015

The MiningBuilding Blueprint in this user's project will not compile. Clicking the compile button never switches it to "Good to Go", and a warning that it needs to be compiled appears at PIE. Repro ...

Crash compiling animation blueprint with Spline IK node

UE - Anim - Rigging - Dec 13, 2016

Crash occurs when compiling an animation blueprint with a Spline IK node. This seems to occur only with the Start and End Bone settings set a certain (perhaps incorrect) way. In the example given, ...

Editor crash when a spline component is added to a blueprint and compiled

Tools - Sep 7, 2016

Most recent user affected CL: 3106830 (4.13.0) Error message: Access violation - code c0000005 (first/second chance not available) Source Context: SelectedKeys = SplineVisualizer->GetSelectedKey ...

Mover Plugin: UNavMoverComponent::GetFeetLocationBased() returns incorrect FBasedPosition when using WalkingMode over a Movable floor, making UPathFollowingComponent erroneously detect a blocked move

UE - Gameplay - Player Movement - Mover - Nov 12, 2025

Function UNavMoverComponent::GetFeetLocationBased() on file "NavMoverComponent.cpp" returns an FBasedPosition built from an FRelativeBaseInfo. The "MovementBaseInfo" is read from key "CommonBlackboa ...

[CrashReport] UObjectBaseUtility::IsA | UObjectProperty::SerializeItem

UE - Gameplay - Aug 15, 2017

This is a trending crash coming out of the 4.17 release. Update: also occurring in 4.18 User DescriptionsCompiled after Refreshing Blueprint node after changine its namePressed compile after creat ...

Hot reload causes placed actor to lose variable references

UE - Foundation - Cpp Tools - Hot Reload - Nov 9, 2017

Preforming a hot reload causes placed actors to lose code based variable settings. More repro steps: 1. Open UE4Editor.exe 2. Create a First Person Code project 3. Build the project for Developme ...