Crash when Background Blur is added with Instanced Stereo enabled

1. Create a Blank Template (any template will do)
2. Enable Instanced Stereo
3. Create a User Widget
4. Add a Background Blur
5. Set the Blur intensity greater than zero (e.g. to 10)

Results: The project will crash with Fatal error: [[Link Removed]|File[Image Removed]:\build++UE5\Sync\Engine\Source\Runtime\RHI\Private\PipelineStateCache.cpp]] [Line: 584] Shader compilation failures are Fatal.

Note: The crash goes away if UI.SlatePostBlurUseDualKawaseFilter is set to 0.

Fatal error: [Link Removed] [Line: 650]
Shader compilation failures are Fatal.

UnrealEditor_RHI!HandlePipelineCreationFailure() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RHI\Private\PipelineStateCache.cpp:650]
UnrealEditor_RHI!InternalCreateGraphicsPipelineState() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RHI\Private\PipelineStateCache.cpp:4548]
UnrealEditor_RHI!PipelineStateCache::GetAndOrCreateGraphicsPipelineState() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RHI\Private\PipelineStateCache.cpp:4668]
UnrealEditor_RHI!SetGraphicsPipelineState() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RHI\Private\PipelineStateCache.cpp:1595]
UnrealEditor_Renderer!SetScreenPassPipelineState() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Renderer\Private\ScreenPass.cpp:272]
UnrealEditor_SlateRHIRenderer!DrawScreenPass<``AddDrawScreenPass<FSlatePostProcessOptimizedKawaseUpsamplePS>'::{{2'::<lambda_1>::operator()'::}}2'::<lambda_1> >() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Renderer\Public\ScreenPass.h:497]
UnrealEditor_SlateRHIRenderer!TRDGLambdaPass<FSlatePostProcessOptimizedKawaseUpsamplePS::FParameters,{{AddDrawScreenPass<FSlatePostProcessOptimizedKawaseUpsamplePS>'::}}2'::<lambda_1> >::Execute() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RenderCore\Public\RenderGraphPass.h:704]
UnrealEditor_RenderCore!FRDGBuilder::ExecutePass() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RenderCore\Private\RenderGraphBuilder.cpp:3494]
UnrealEditor_RenderCore!FRDGBuilder::ExecuteSerialPass() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RenderCore\Private\RenderGraphBuilder.cpp:3516]
UnrealEditor_RenderCore!FRDGBuilder::SetupAuxiliaryPasses() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RenderCore\Private\RenderGraphBuilder.cpp:2614]
UnrealEditor_RenderCore!FRDGBuilder::SetupParameterPass() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RenderCore\Private\RenderGraphBuilder.cpp:2643]
UnrealEditor_SlateRHIRenderer!FRDGBuilder::AddPassInternal<FSlatePostProcessOptimizedKawaseUpsamplePS::FParameters,{{AddDrawScreenPass<FSlatePostProcessOptimizedKawaseUpsamplePS>'::}}2'::<lambda_1> >() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RenderCore\Public\RenderGraphBuilder.inl:271]
UnrealEditor_SlateRHIRenderer!AddSlateKawaseBlurUpsamplePass() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\SlateRHIRenderer\Private\SlatePostProcessor.cpp:585]
UnrealEditor_SlateRHIRenderer!AddSlateKawaseBlur() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\SlateRHIRenderer\Private\SlatePostProcessor.cpp:614]
UnrealEditor_SlateRHIRenderer!AddSlatePostProcessBlurPass() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\SlateRHIRenderer\Private\SlatePostProcessor.cpp:794]
UnrealEditor_SlateRHIRenderer!AddSlateDrawElementsPass() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\SlateRHIRenderer\Private\SlateRHIRenderingPolicy.cpp:1719]
UnrealEditor_SlateRHIRenderer!FSlateRHIRenderer::DrawWindowViewport_RenderThread() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\SlateRHIRenderer\Private\SlateRHIRenderer.cpp:828]
UnrealEditor_SlateRHIRenderer!FSlateRHIRenderer::DrawWindow_RenderThread() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\SlateRHIRenderer\Private\SlateRHIRenderer.cpp:1047]
UnrealEditor_SlateRHIRenderer!FSlateRHIRenderer::DrawWindows_RenderThread() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\SlateRHIRenderer\Private\SlateRHIRenderer.cpp:1351]
UnrealEditor_SlateRHIRenderer!{{FSlateRHIRenderer::DrawWindows_Private'::}}76'::<lambda_3>::operator()() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\SlateRHIRenderer\Private\SlateRHIRenderer.cpp:1620]
UnrealEditor_SlateRHIRenderer!FRenderThreadCommandPipe::Enqueue<TRenderCommandTag<{{FSlateRHIRenderer::DrawWindows_Private'::}}76'::TSTR_SlateDrawWindowsCommand1617>,TUniqueFunction<void __cdecl(FRHICommandListImmediate &)> >() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RenderCore\Public\RenderingThread.h:519]
UnrealEditor_SlateRHIRenderer!FRenderCommandDispatcher::Enqueue<TRenderCommandTag<{{FSlateRHIRenderer::DrawWindows_Private'::}}76'::TSTR_SlateDrawWindowsCommand1617> >() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\RenderCore\Public\RenderingThread.h:1014]
UnrealEditor_SlateRHIRenderer!FSlateRHIRenderer::DrawWindows_Private() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\SlateRHIRenderer\Private\SlateRHIRenderer.cpp:1617]
UnrealEditor_Slate!FSlateApplication::PrivateDrawWindows() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:1512]
UnrealEditor_Slate!FSlateApplication::DrawWindows() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:1193]
UnrealEditor_Slate!FSlateApplication::TickAndDrawWidgets() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:1798]
UnrealEditor_Slate!FSlateApplication::Tick() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:1648]
UnrealEditor!FEngineLoop::Tick() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5973]
UnrealEditor!GuardedMain() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Launch\Private\Launch.cpp:190]
UnrealEditor!GuardedMainWrapper() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:123]
UnrealEditor!LaunchWindowsStartup() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:277]
UnrealEditor!WinMain() [D:\VB_RedBox_FNMain\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:336]
UnrealEditor!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll