Crash When Trying to Draw a Material to a Render Target where Source Material is using AlphaComposite + Unlit Mode

The issue occurs when trying to Draw a Material to a Render Target where the source material is using AlphaComposite + Unlit mode. This is an attempt at the solution proposed by Ryan Brucks to allow the user to assemble all 4 channels for their (packed) texture.

Log:
[Link Removed]
[Link Removed]

1. Download and open the attached project: [Link Removed]
2. PIE: Stand alone game
   RESULT: Game crashes with the attached Callstack
   EXPECTED: Game to play, material to render correctly
   NOTE: The assets causing the crash are located in the "Test" folder in the Content Browser

UE4Editor_Renderer!FSceneRenderTargets::GetSceneColorForCurrentShadingPath() scenerendertargets.h:678
UE4Editor_Renderer!FSceneTextureShaderParameters::Set<FRHIVertexShader * __ptr64,FRHICommandList>() scenerendertargets.cpp:2406
UE4Editor_Renderer!FDeferredPixelShaderParameters::Set<FRHIVertexShader * __ptr64,FRHICommandList>() scenerendertargets.cpp:2578
UE4Editor_Renderer!FMaterialShader::SetParameters<FRHIVertexShader * __ptr64>() shaderbaseclasses.cpp:324
UE4Editor_Renderer!TBasePassVertexShaderPolicyParamType<FUniformLightMapPolicyShaderParametersType>::SetParameters() basepassrendering.h:373
UE4Editor_Renderer!TBasePassDrawingPolicy<FUniformLightMapPolicy>::SetSharedState() basepassrendering.h:1054
UE4Editor_Renderer!FDrawTranslucentMeshAction::Process<FUniformLightMapPolicy>() translucentrendering.cpp:393
UE4Editor_Renderer!ProcessBasePassMesh<FDrawTranslucentMeshAction>() basepassrendering.h:1547
UE4Editor_Renderer!FTranslucencyDrawingPolicyFactory::DrawMesh() translucentrendering.cpp:561
UE4Editor_Renderer!FTranslucencyDrawingPolicyFactory::DrawDynamicMesh() translucentrendering.cpp:615
UE4Editor_Renderer!FRendererModule::DrawTileMesh() renderer.cpp:119
UE4Editor_Engine!FTileRenderer::DrawTile() tilerendering.cpp:196
UE4Editor_Engine!<lambda_96f8fbb649005e3350d0fb3e118cb9e8>::operator() tilerendering.cpp:350
UE4Editor_Engine!TGraphTask<TEnqueueUniqueRenderCommandType<`FCanvasTileRendererItem::Render_GameThread'::`2'::DrawTileCommandName,<lambda_96f8fbb649005e3350d0fb3e118cb9e8> > >::ExecuteTask() taskgraphinterfaces.h:883
UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() taskgraph.cpp:954
UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilQuit() taskgraph.cpp:701
UE4Editor_RenderCore!RenderingThreadMain() renderingthread.cpp:325
UE4Editor_RenderCore!FRenderingThread::Run() renderingthread.cpp:459
UE4Editor_Core!FRunnableThreadWin::Run() windowsrunnablethread.cpp:76