How do I setup toolbox so I can share assemblies without the fastners going strange?

SW 2015 toolbox  & Win 7 OS.

I'm using Google Drive to share files with clients over the internet.  When the client opens my assembly many, but not all, fasteners go haywire (balloons into another fastener).

Is this simply a setting in toolbox or do I need to create a separate toolbox and share it?  The client is clearly using their own toolbox which is different from mine.

SolidworksToolbox