Unreal Engine Issues
Unreal Engine Issues
Client PlayerState is null on joining online session
UE - Networking - Jul 31, 2015APlayerController::ClientStartOnlineSession() checks PlayerState at the start of a game after loading a level. Due to time needed to load in, client player state may may return NULL ...
Hierarchical LODs used with Precomputed Visibility cause actors to occlude that should not behind translucent materials
UE - Graphics Features - Jul 6, 2016When using Precomputed Visibility in conjunction with HLODs and translucent materials without them culling actors occluded by the translucent material. The example gif attached shows that the base ...
Always Relevant actor may replicate incorrect movement mode when the walkable floor becomes irrelevant
UE - Gameplay - Player Movement - Feb 26, 2024When the character class is set to always relevant, if a client travels very far away from another character, such that the character is relevant but the component they're standing on is not (but al ...
FBlackboardKeySelector filters aren't applied when recompiling blueprint if a behavior tree asset containing the blueprint added as a service is closed, or if the blueprint is reparented.
UE - AI - BehaviorTree - Sep 24, 2025Context In Behavior Trees, BT Services can be added to nodes. Those services can have configurable FBlackboardKeySelectors. BlackboardKeys are variables on a blackboard that the behavior tree can r ...
Crash When Toggling Visibility of Level with Planar Reflection
UE - LD & Modeling - Terrain - Landscape - Mar 26, 2018This crash occurs in 4.19 and 4.20 but not 4.18. Repro'd in 4.19.0-3944462 and 4.20.0-3955769 and 3964322. This is a regression. Per UDN licensee: When I'm showing/hiding levels in editor (in le ...
Renaming a Blackboard Key removes it's references in the Behavior Tree
UE - AI - Jan 27, 2015Renaming a Blackboard Key removes it's references in the Behavior Tree ...
Niagara - When Interpolated Spawning is disabled, the first frame of each particle unexpectedly does not take into account the Particle Update stage
UE - Niagara - Feb 28, 2025Foreword: Even if the behavior described here is by design, it is rarely (if ever) expected or desired. This was discussed and agreed to be treated as a bug. Explanation below. When interpolated sp ...
Collision of child actor doesn't rotate if the parent is simulating physics
UE - Simulation - Physics - Aug 11, 2015Collision of child actor doesn't rotate if the parent is simulating physics. This was an old bug that an AnswerHub user reported back in 4.9 but now a licensee is reporting this same behavior in 4.1 ...
Internal Compiler error when calling a custom enum in a struct from a blueprint macro
UE - Gameplay - Blueprint - Aug 6, 2015If a macro is referencing a custom enum within a struct and compiled after another output pin is removed, an internal compiler error will appear and the blueprint will not compile. ...
Crash with for loop and TArray in constructor to generate multiple StaticMeshComponents
UE - Foundation - Core - Apr 20, 2015Using a TArray to store multiple components being setup inside a for loop of a constructor will crash on project open. Crash Reporter: [Link Removed] ...