iOS builds fail on Windows.

UE - Platform - Mobile - May 15, 2026

Loading Windows installed iOs mobile provisioning profiles fails at start of iOS build from windows machine. This due to a recent change that attempts to load PKCS12 from mobileprovision files. Thes ...

FarShadow range not considered in GetViewDependentWholeSceneProjectedShadowInitializer

UE - Platform - Mobile - Mar 30, 2026

Cascade index 0 is passed into GetViewDependentWholeSceneProjectedShadowInitializer. I think the intent of MaxShadowCascades = 1 and requesting cascade index 0 is to get a single bounding volume for ...

OverrideVertexColor causes a crash on mobile renderer

UE - Platform - Mobile - Jan 8, 2026

Setting Allow CPU Access on the mesh, or setting bSupportsManualVertexFetch=1 in Engine.ini, avoids the crash. ...

OcclusionFeedback may not be performant for primitives with large screensize

UE - Platform - Mobile - Dec 13, 2025

A licensee reported that the performance could be worse in some scenarios (probably a small scene with large objects) with OcclusionFeedback enabled ( 20fps up if disabled), tested on a Qualcomm 870 ...

Missing UV Clamping or Clear in SunAlphaPS_Mobile

UE - Platform - Mobile - Nov 13, 2025

In: void SunAlphaPS_Mobile( float2 InUVs[8] : TEXCOORD0, in FStereoPSInput StereoInput, out HALF_TYPE OutColor : SV_Target0 ) { OutColor =  SunUnBias(SunShaftAndDofTexture.Sample(SunShaftAndDo ...

VulkanStagingBuffers stat continually to grows.

UE - Platform - Mobile - Oct 24, 2025

On Android phones, VulkanStagingBuffers continually grows when the scene is static. From looking at FStagingManager, it appears the VulkanStagingBuffers atat is only updated on buffer acquisition, ...

Shader Complexity View not working in Deferred Mobile Preview

UE - Platform - Mobile - Sep 30, 2025

Proposed workaround:add in FMobileSceneRenderer::RenderDeferredMultiPass (MobileShadingRenderer.cpp): #if WITH_DEBUG_VIEW_MODES if (ViewFamily.UseDebugViewPS()) { return; } #endif // WITH_DEBU ...

[Mobile/Forward Rendering] PlanarReflection does not work when the reflection plane faces certain directions

UE - Platform - Mobile - Sep 24, 2025

Note: This repros on 4.27 and all 5.x versions. When using the mobile renderer and/or forward shading, Planar Reflection will simply not work if the reflection plane normal has components that add ...

NaN Present on IOS after UE5.6 Because of Removal of MobileSpecularGGX

UE - Platform - Mobile - Sep 24, 2025

In UE5.6 MobileSpecularGGX was removed and now mobile devices also run D_GGX. The problem is that there are still cases where very bright values are produced (image 1) and thus NaNs appear in the Bl ...