Particle Random Value is the same for all particles with a Niagara Mesh Renderer

UE - Rendering - Architecture - Niagara - Sep 28, 2026

A material using the Particle Random Value node returns the same value for every particle drawn by a Niagara Mesh Renderer. Particle transforms are not affected, only the random value. This happens ...

[CrashReport] Couldn't find Shader TShadowDepthVSVertexShadowDepth_OutputDepthPositionOnly

UE - Graphics Features - Sep 7, 2017

This is a common crash that has occurred since at least 4.16. The one user comment mentions a plugin, but many of the crashes occur on vanilla builds. User DescriptionsVaTexAltlas plugin enabled i ...

Out-of-Bounds Access During Partial Updates of ISMC Per-Instance Custom Data

UE - Rendering - Features - Jan 6, 2026

When using instance custom data values, removing an instance and changing the number of custom data floats in sequence can cause an array-out-of-bounds crash. The underlying arrays are not resized ...

RHIGetAvailableResolutions returns duplicate entries when bIgnoreRefreshRate is false

UE - Rendering - Architecture - RHI - Sep 17, 2015

When the RHIGetAvailableResolutions function fills the array that is passed in as the first argument, it will end up filling some slots with duplicate resolutions (including refresh rate) when the b ...

Crash report window does not open on GitHub source builds

UE - Foundation - Core - CrashReportClient - Jun 13, 2016

When using a source build of 4.12, the crash report client window does not open even if Crash Report Client is manually built alongside the editor. UPDATE: Only affecting Source builds from Github. ...

Preview Instance can still trigger print strings when you PIE

OLD - Anim - Apr 10, 2015

In the given answerhub example, the user has a print string coming from IsNotValid on a check of *TryGetPawnOwner*. This is returning a false negative to him when he PIE's because the Preview insta ...

Can only preview one camera from a Blueprint actor in the level viewport

Tools - Mar 24, 2015

Selecting a blueprint with a camera in it will allow you to preview the camera, but if your blueprint has more than one camera you can only preview the highest one in its heirarchy. With the abilit ...

LIVE: Transform Variable rotation not setting correctly

UE - Gameplay - Oct 21, 2014

When trying to set the rotation value of a blueprint transform variable, changing the Y value will usually reset to 0 and change the value of X and Z as well. ...

Output log spams errors if blueprint variable is right clicked

UE - Gameplay - Blueprint - Apr 16, 2015

Errors spam in output log when any variable is right clicked in the blueprint event graph. Update: This seems to occur only in character blueprints. Attempted in Actor BP with no success. ...

Default value for struct cannot be set to same value as parent in child blueprint

UE - Gameplay - Blueprint - Jan 29, 2015

Child blueprint cannot set value of inherited struct variable to same value as parent. ...