[CrashReport] UE4Editor_Engine!FUniformExpressionSet::CreateUniformBuffer() [materialuniformexpressions.cpp:354]

  339       
  340       		void** ResourceTable = (void**)((uint8*)TempBuffer + UniformBufferStruct->GetLayout().ResourceOffset);
  341       		check(((UPTRINT)ResourceTable & 0x7) == 0);
  342       
  343       		check(UniformBufferStruct->GetLayout().Resources.Num() == Uniform2DTextureExpressions.Num() * 2 + UniformCubeTextureExpressions.Num() * 2 + 2);
  344       
  345       		// Cache 2D texture uniform expressions.
  346       		for(int32 ExpressionIndex = 0;ExpressionIndex < Uniform2DTextureExpressions.Num();ExpressionIndex++)
  347       		{
  348       			const UTexture* Value;
  349       			ESamplerSourceMode SourceMode;
  350       			Uniform2DTextureExpressions[ExpressionIndex]->GetTextureValue(MaterialRenderContext,MaterialRenderContext.Material,Value,SourceMode);
  351       
  352       			// gmartin: Trying to locate UE-17608
  353 ***** 			checkf(!Value || Value->IsValidLowLevel(), TEXT("Texture not valid! UE-17608! Parameter (%s)"),
  354       				   Uniform2DTextureExpressions[ExpressionIndex]->GetType() == &FMaterialUniformExpressionTextureParameter::StaticType ?
  355       				   	*((FMaterialUniformExpressionTextureParameter&)*Uniform2DTextureExpressions[ExpressionIndex]).GetParameterName().ToString() : TEXT("non-parameter"));
  356       
  357       			if (Value && Value->Resource)
  358       			{
  359       				//@todo-rco: Help track down a invalid values
  360       				checkf(Value->IsA(UTexture::StaticClass()), TEXT("Expecting a UTexture! Value='%s' class='%s'"), *Value->GetName(), *Value->GetClass()->GetName());
  361       
  362       				// UMaterial / UMaterialInstance should have caused all dependent textures to be PostLoaded, which initializes their rendering resource
  363       				checkf(Value->TextureReference.TextureReferenceRHI, TEXT("Texture %s of class %s had invalid texture reference"), *Value->GetName(), *Value->GetClass()->GetName());
  364       
  365       				*ResourceTable++ = Value->TextureReference.TextureReferenceRHI;
  366       				FSamplerStateRHIRef* SamplerSource = &Value->Resource->SamplerStateRHI;
  367       
  368       				if (SourceMode == SSM_Wrap_WorldGroupSettings)