Unreal Nvidia Developer Caustics advice

Can anybody advise on Nvidia Developer caustics please?

On the right is a stained glass window from the project files, on the left is my scene with the same texture however the light does not come through. I have compared all material, light and project settings which are exactly the same. Both running in same version.

Also as a side note some of my particle FX textures do not show either…

Does anybody know why?