cannot open program - Image Not found

i was recommended to download draftsight by a friend, so far all I'm having is problems. I've downloaded the installer (mac osx version) and when i open all i get is error messages 

Dyld Error Message: Library not loaded: /usr/lib/libc++.1.dylib Referenced from: /Volumes/DraftSight/DraftSight.app/Contents/MacOS/../Frameworks/QtWebKitWidgets Reason: image not found

i can provide more info if needed

thank you,

Jeffery