Speedtree Grass crashing unreal engine.

Hi Guys,
Hi guys I’m trying to import grass from speedtree to unreal.
Speedtree for unreal engine v7.1.4 is crashing unreal engine 4.10.4.
It doesn’t create a crash dump so I can’t be sure what is crashing it.
Other speed tree things import fine. Does anyone know whats causing this ?
Cheers,