Here are some details, facts and suggestions in no particular order: You can download the new installer from the usual location. There was a snag which prevents us from releasing an updated version and we won't be able to fix this until Rhino 5 SR1, though that shouldn't be all that far off as we've already been typing on SR1 for several weeks. Today we are re-releasing with an updated installer that will install Grasshopper on all Rhino 5 installations on a system, be they 32 or 64 bit. As of today, Grasshopper is officially a Rhino 5 only plug-in.
Grasshopper and Rhino 4 no longer get along and Grasshopper has decided it's time to move out.
