Unreal Engine Issues
Unreal Engine Issues
Physics replication is not working correctly and clients receive different results
UE - Simulation - Physics - Aug 9, 2018Physics replication is not working properly. The replicated physics are different than what is on the server. The user who reported this issue pointed out this line as well which seems to not do any ...
Crash when removing and re-adding instances to an InstancedStaticMeshComponent with PerInstanceCustomData.
UE - World Creation - Worldbuilding Tools - Jan 22, 2026When using an InstancedStaticMeshComponent with PerInstanceCustomData, the number of float elements in the "Custom Data" array should always be equal to NumCustomDataFloats multiplied by the number ...
Lighting behavior is unreliable for translucent lit materials, results are inconsistent depending on the editor camera's FOV and the editor viewport's width/height/aspect
UE - Rendering - Architecture - Oct 27, 2024When working on the level editor viewport or testing on PIE, the visual appearance of additive/translucent lit materials changes significantly (and abruptly) when varying the camera FOV or the viewp ...
Camera behavior during "Orbit Pan Mode" (Alt+MMB+Drag) is wrong while piloting an actor
UE - Editor - Developer Usability - Nov 18, 2025In the Level Editor, dragging the mouse while the "Alt" key is pressed performs one of the "Orbit" movements: OrbitRotation, OrbitPan, OrbitZoom. The same can be done while Piloting an actor. Howev ...
[CrashReport] UE4Editor_CoreUObject!FWeakObjectPtr::operator=() [weakobjectptr.cpp:28]
UE - Anim - Sequencer - Nov 3, 2016This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Access violation - code c0000005 (first/second chance not available) Source C ...
[AI] EQS incorrectly sorts when auto-sort in single-item mode when there is only one filtering and one scoring test.
UE - AI - EQS - Dec 14, 2021EQS places a cheap filter as the last step of a query when using auto-sort for single item results if there is only one filter. Found via [Link Removed] which is quoted below:Environmental Query sys ...
NPC - Does not get updates from Material Parameter Collection changes in the editor
UE - Niagara - Sep 30, 2024When an MPC is selected as the Source Material Collection for an NPC, all of its current parameters are carried over to the NPC with their current values. After that, if parameters are added to, rem ...
Actor variable type has distractingly large tooltip comment
UE - Gameplay - Blueprint Editor - May 4, 2021Actor.h has a large comment that describes the entire lifecycle of Actors, which was written for the API website (https://docs.unrealengine.com/en-US/API/Runtime/Engine/GameFramework/AActor/index.ht ...
Properties not serialized when moving actor/component depending on unrelated specifiers
UE - Framework - Blueprint - Sep 25, 2023When an actor is moved on the level editor viewport, it is reconstructed along with its components, which at first makes their properties reset to their default state. Thankfully, this does not happ ...
Asset Registry GetDerivedClassNames does not work properly during editor startup
UE - Foundation - Core - Jun 25, 2020This bug comes from https://udn.unrealengine.com/questions/585499/view.html which describes a problem where a licensee is trying to use the AssetManager to scan a primary asset type that is generate ...