Sorry to hear you're facing those troubles. At first sight, there's nothing wrong with your set-up and all should be working correctly (and upon our internal tests it is). We're running some more internal test here, but up to now we can't reproduce your troubles.
Unfortunately, the generated minidump it doesn't clear at all. The error is produced inside of the V-Ray renderer, but we can't trace it down completely and I'm afraid we can't do much more in this case (like debug the rendering process).
Let me point out, that we always recommend to use the latest version released as we've already fixed some bugs and it might be something related to an already solved issue. Therefore I would advice you to proceed the installation of the latest Forest Pack version / try to upgrade to a newer V-Ray version to check if there is any difference.