Can't get opacity in VRayLightMtl to work with RT CUDA

[Alex_M]

I wanted to try and render some candles with Vray RT and VRayLightMtl where the flames are made from a plane with a texture. The flames however come out with black background as if opacity does not work even though I have a texture in the opacity slot. It works fine with Adv. I took a quick look at the docs and it says that VRayLightMtl is supported apart from the direct illumination option. Please see screenshot below:

[matanov]

The "multiply color by opacity" option is still not supported in GPU. Is this your case?

[Alex_M]

No, I'm not using "multiply color by opacity". I've just got the same texture in the "Color" and "Opacity" slots.