edge mode in vray 6 gpu

[grue]

i'm getting an error in vray 6, update 2.1 (6.20.06 build 00000) and forestPro 8.2.6.702

i'm loading a preset lawn, layered lawn, or autumn leaves and applying it to a circle spline with a hole in it and an edit poly modifier.

when i switch from point mode to size mode, it works just fine and i see it update in my viewport.

when i switch to edge mode, i get an error that say "Edge mode is not supported for the current render. See documentation for details. point mode will be used instead"

now, i opened a scene from about 6 months ago (created in an earlier version of vray and forestpro) and those rendered just fine, i confirmed the grass were set to edge mode.

i have been using Vray GPU in RTX mode for just over a year now.  The video card drivers are appropriate for Vray GPU, sometimes they lag behind a version or two.

I switched my Vray GPU to CUDA mode, started an IPR render while in Point mode for the forest object, then i stopped the IPR and switched to edge mode and the error went away and it was working.

Finally, i stopped all IPR rendering, switched back to RTX mode, and switched between Point - Size - Edge mode and got no errors.  The edge mode even worked as expected.  Oh and I also switched to one of the Large gravel presets having deleted all the leaves in the Geometry rollout, clicking on library and imported a Large gravel preset.

so this is all very interesting.  thanks.