Disabling LQ lightmaps causes crash on mobile preview

 Fatal error: [File:D:\Projects\HD\UnrealEngine\Engine\Source\Runtime\Engine\Private\Materials\MaterialShared.cpp] [Line: 1776] 
 Couldn't find Shader TMobileBasePassVSTDistanceFieldShadowsAndLightMapPolicyLQHDRLinear64 for Material Resource WorldGridMaterial!
  With VF=FLocalVertexFactory, Platform=PCD3D_ES31
  ShouldCache: Mat=1, VF=1, Shader=0 
  MaterialUsageDesc: LightingModel=MSM_DefaultLit, BlendMode=BLEND_Opaque, SpecialEngine=1, TwoSided=0, TSNormal=1, Masked=0, Distorted=0, WritesEveryPixel=1, ModifiesMeshPosition=0, Usage={}
 
 
 UE4Editor_Core!FDebug::AssertFailed() [d:\projects\hd\unrealengine\engine\source\runtime\core\private\misc\assertionmacros.cpp:332]
 UE4Editor_Engine!FMaterial::GetShader() [d:\projects\hd\unrealengine\engine\source\runtime\engine\private\materials\materialshared.cpp:1767]
 UE4Editor_Renderer!GetUniformMobileBasePassShaders<11,0>() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\mobilebasepassrendering.h:536]
 UE4Editor_Renderer!GetMobileBasePassShaders<FUniformLightMapPolicy,0>::GetMobileBasePassShaders<FUniformLightMapPolicy,0>() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\mobilebasepassrendering.h:613]
 UE4Editor_Renderer!FDrawMobileBasePassStaticMeshAction::AddMeshToStaticDrawList<FUniformLightMapPolicy>() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\mobilebasepassrendering.cpp:246]
 UE4Editor_Renderer!FDrawMobileBasePassStaticMeshAction::Process<0>() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\mobilebasepassrendering.cpp:236]
 UE4Editor_Renderer!ProcessMobileBasePassMesh<FDrawMobileBasePassStaticMeshAction,0>() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\mobilebasepassrendering.h:1052]
 UE4Editor_Renderer!FMobileBasePassOpaqueDrawingPolicyFactory::AddStaticMesh() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\mobilebasepassrendering.cpp:297]
 UE4Editor_Renderer!FStaticMesh::AddToDrawLists() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\scenecore.cpp:377]
 UE4Editor_Renderer!FPrimitiveSceneInfo::AddStaticMeshes() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\primitivesceneinfo.cpp:146]
 UE4Editor_Renderer!FPrimitiveSceneInfo::AddToScene() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\primitivesceneinfo.cpp:189]
 UE4Editor_Renderer!FScene::AddPrimitiveSceneInfo_RenderThread() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\rendererscene.cpp:467]
 UE4Editor_Renderer!`FScene::AddPrimitive'::`2'::EURCMacro_FAddPrimitiveCommand::DoTask() [d:\projects\hd\unrealengine\engine\source\runtime\renderer\private\rendererscene.cpp:705]
 UE4Editor_Renderer!TGraphTask<`FScene::AddPrimitive'::`2'::EURCMacro_FAddPrimitiveCommand>::ExecuteTask() [d:\projects\hd\unrealengine\engine\source\runtime\core\public\async\taskgraphinterfaces.h:868]
 UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() [d:\projects\hd\unrealengine\engine\source\runtime\core\private\async\taskgraph.cpp:932]
 UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilQuit() [d:\projects\hd\unrealengine\engine\source\runtime\core\private\async\taskgraph.cpp:679]
 UE4Editor_RenderCore!RenderingThreadMain() [d:\projects\hd\unrealengine\engine\source\runtime\rendercore\private\renderingthread.cpp:320]
 UE4Editor_RenderCore!FRenderingThread::Run() [d:\projects\hd\unrealengine\engine\source\runtime\rendercore\private\renderingthread.cpp:454]
 UE4Editor_Core!FRunnableThreadWin::Run() [d:\projects\hd\unrealengine\engine\source\runtime\core\private\windows\windowsrunnablethread.cpp:74]