Hmmm which engine version are you using. It could be that the definition of SceneTextureLookup changed.
If you go to Window -> HLSL Code in the menu. You can see the Materials HLSL code. In there you can find the definition of the SceneTextureLookup function. (Copy the contents of that window to a text editor to make searching easier.)
This should give in my Engine Version (4.6.1) it’s defined as
float4 SceneTextureLookup(float2 UV, int SceneTextureIndex, bool bFiltered)
{ .... }
That may have changed. I suspect that the last bool Parameter is not there in your Version.
Change the SceneTextureLookup-function calls accordingly and it should work.
If you need a reference. There is a GetMaterialEmissiveRaw(FMaterialPixelPArameters Parameters) function in you Materials HLSL code that should also call the SceneTextureLookup function.
I kind of feared that there would be differences in previous and futures engine versions that would break this (just like most C++ code needs changes with every update). But it seems like something you can fix.