Forest Pack Edge mode shadows error

[jironomo]

Getting a strange shadow problem when using forest pack edge mode to get nice clean grass edges. I'm using the latest version of forest pack (5.3.2) and vray 3.50.04 cpu mode and have a relatively straight forward grass object scattered on a plane.... when I tick edge mode to get the nice clean boundary edges I am getting this weird shadow on the kerb....

See attached. Any ideas how to fix this?

So far I have tried:

increasing the Max transp. levels to 500 - this doesn't help at all.
increasing secondary ray bias - this doesn't help at all.
increase density of forest pack (reduce units in distribution map rollout) - this makes it worse
Using a spline area instead of a plane to scatter grass on to - this this doesn't help at all.

[svetlozar.draganov]

Would it be possible to attach that scene for investigation?

[Vizioen]

Are you sure it's a shadow, maybe it's something else? Have you checked your render elements?

[dlparisi]

Perhaps VrayDirt on the Concrete curb? I recall Dirt still "seeing" the hidden forest pack models.

[jironomo]

Thanks Dlparisi... you were exactly right. Vray dirt map on kerb is still seeing the hidden forest pack models. I excluded the grass forest in the 'result affect' of the vray dirt map and it has fixed the problem.