This is a common crash among the community since at least the 4.14 release. Additional information is not currently available. This is spread among numerous different CrashGroups between releases with some variation in the Callstacks.
Some example crashGroups
User Descriptions
Source Context
2094 private: 2095 /** Stored off position of the original archive we are wrapping. */ 2096 int64 OriginalPosition; 2097 }; 2098 2099 inline void FShader::CheckShaderIsValid() const 2100 { 2101 ***** checkf(Canary == ShaderMagic_Initialized, 2102 TEXT("FShader %s is %s. Canary is 0x%08x."), 2103 Canary == ShaderMagic_Uninitialized ? GetType()->GetName() : TEXT("[invalid]"), 2104 Canary == ShaderMagic_Uninitialized ? TEXT("uninitialized") : TEXT("garbage memory"), 2105 Canary 2106 );
repro steps currently unknown
Assertion failed: Canary == ShaderMagic_Initialized [File:d:\build\++ue4+release-4.16+compile\sync\engine\source\runtime\shadercore\public\Shader.h] [Line: 2107] FShader [invalid] is garbage memory. Canary is 0xdc67f93b. UE4Editor_ShaderCore!FShader::CheckShaderIsValid() [shader.h:2051] UE4Editor_Renderer!FMaterialShader::SetParameters<FRHIVertexShader * __ptr64>() [shaderbaseclasses.cpp:191] UE4Editor_Renderer!TBasePassVertexShaderPolicyParamType<FUniformLightMapPolicyShaderParametersType>::SetParameters() [basepassrendering.h:373] UE4Editor_Renderer!TBasePassDrawingPolicy<FUniformLightMapPolicy>::SetSharedState() [basepassrendering.h:1054] UE4Editor_Renderer!TStaticMeshDrawList<TBasePassDrawingPolicy<FUniformLightMapPolicy> >::DrawElement<2>() [staticmeshdrawlist.inl:132] UE4Editor_Renderer!TStaticMeshDrawList<TBasePassDrawingPolicy<FUniformLightMapPolicy> >::DrawVisibleInner<2>() [staticmeshdrawlist.inl:348] UE4Editor_Renderer!TStaticMeshDrawList<TBasePassDrawingPolicy<FUniformLightMapPolicy> >::DrawVisible() [staticmeshdrawlist.inl:400] UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderBasePassStaticDataType() [basepassrendering.cpp:883] UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderBasePassStaticData() [basepassrendering.cpp:999] UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderBasePassView() [basepassrendering.cpp:1229] UE4Editor_Renderer!FDeferredShadingSceneRenderer::RenderBasePass() [basepassrendering.cpp:864] UE4Editor_Renderer!FDeferredShadingSceneRenderer::Render() [deferredshadingrenderer.cpp:910] UE4Editor_Renderer!RenderViewFamily_RenderThread() [scenerendering.cpp:1728] UE4Editor_Renderer!TGraphTask<`FRendererModule::BeginRenderingViewFamily'::`21'::EURCMacro_FDrawSceneCommand>::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]
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-46018 in the post.