Maximum number of State Machine connections?

OLD - Anim - Mar 16, 2015

Adding more than 8 connections to or from a state in the state machine results in unpredictable behavior, like causing an animation to fail. (See image.) Was able to reproduce with user's test file ...

FStateTreeRunParallelStateTreeTask and TStateTreePropertyRef

UE - AI - StateTree - Dec 2, 2025

When using a state tree that has a StateTreePropertyRef as a parameter in parallel any references will fail to resolve using the GetPropertyRef node. ...

Changes made to default values in a subobject nested within a subobject are not propagated to child Blueprints

UE - Gameplay - Blueprint - Jul 6, 2018

When a Blueprint contains multiple layers of nested subobjects, any subobjects below the top-most layer do not have changes to their properties propagate to child Blueprints. See attached project (c ...

In editor, sub level instance's streaming state persists incorrectly after toggling Level Behavior without saving

UE - World Creation - Worldbuilding Tools - Level Instances - Jun 11, 2025

When adding a sub level with world partition streaming to a main level where the streaming is also enabled, setting* Level Behavior* of the sub level to Standalone, and saving the result, in the fir ...

Hot Reload does not update blueprint pins

UE - Gameplay - Blueprint - Jan 15, 2015

When changing the variable type or return type of a function in code and hot reload in the editor, blueprints that use the variable/function do not have their pins updated until the editor is closed ...

iOS Shipping Build using std::thread crashes on launch

UE - Platform - Mobile - Jun 2, 2017

A user is reporting that using the following code in a GameMode class causes shipping iOS packages to crash on launch:void ANOGSSDKGameModeBase::StartPlay() { std::thread([](){ std::clog << "THRE ...

Classes in TargetDenyList modules are still referenced from Components on BlueprintGeneratedClasses and cause runtime warnings

UE - Core - Systems - Feb 25, 2024

Other than the presence of the error and the performance cost of looking for a package on disk that does not exist, there are no behavioral problems. When running with legacy (non-iostore) pakfiles ...

Using GENERATED_BODY() instead of GENERATED_UINTERFACE_BODY() in an Interface code class results in a UHT crash when trying to build the project.

UE - Foundation - Core - Mar 3, 2015

Replacing GENERATED_UINTERFACE_BODY() with GENERATED_BODY() in 4.7.0 or above results in an Unreal Header Tool crash and build failure in Visual Studio. This was working in 4.6.1, but when tested i ...

MetalRHI crash locking camera cut to a level sequence in QAGame

UE - Platform - Apple - May 12, 2016

Running into an intermittent crash in MetalRHI when locking to a camera cut in a level sequence. Very similar to [Link Removed] which is an NVIDIA GPU. ...