Crash occurs when Switching between Engine Scalability Settings after Adding Landscape Material

A crash occurs when the licensee modifies the engine scalability settings after clearing and reapplying a landscape material.

1. Open the engine in visual studio.
2. Edit the ShaderVersion.usf source file by adding a space somewhere to force it to recompile.
3. Open the project in the associated engine version.
4. Open the StefRepro map
5. Clear the Landscape Material from its slot, and then re-apply the material.
6. Begin switching the Engine Scalability Settings to different values (i.e Medium, High, Epic)

Outcome Crash occurs

Expected No crash occurs

UE4Editor_Renderer!FMaterialShader::SetParameters<FRHIVertexShader * __ptr64>() shaderbaseclasses.cpp:186
UE4Editor_Renderer!TBasePassVertexShaderPolicyParamType<FUniformLightMapPolicyShaderParametersType>::SetParameters() basepassrendering.h:290
UE4Editor_Renderer!TBasePassDrawingPolicy<FUniformLightMapPolicy>::SetSharedState() basepassrendering.h:945
UE4Editor_Renderer!FDrawBasePassDynamicMeshAction::Process<FUniformLightMapPolicy>() basepassrendering.cpp:499
UE4Editor_Renderer!ProcessBasePassMesh<FDrawBasePassDynamicMeshAction>() basepassrendering.h:1468
UE4Editor_Renderer!FBasePassOpaqueDrawingPolicyFactory::DrawDynamicMesh() basepassrendering.cpp:575
UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderBasePassDynamicData() basepassrendering.cpp:939
UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderBasePass() basepassrendering.cpp:761
UE4Editor_Renderer!FDeferredShadingSceneRenderer::Render() deferredshadingrenderer.cpp:872
UE4Editor_Renderer!RenderViewFamily_RenderThread() scenerendering.cpp:1849
UE4Editor_Renderer!TGraphTask<`FRendererModule::BeginRenderingViewFamily'::`21'::EURCMacro_FDrawSceneCommand>::ExecuteTask() taskgraphinterfaces.h:868
UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() taskgraph.cpp:932
UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilQuit() taskgraph.cpp:679
UE4Editor_RenderCore!RenderingThreadMain() renderingthread.cpp:319
UE4Editor_RenderCore!FRenderingThread::Run() renderingthread.cpp:440
UE4Editor_Core!FRunnableThreadWin::Run() windowsrunnablethread.cpp:74