I see an old thread on this topic, but I have just installed Sketchup Make 2016 (on 8/4/2016) on my macbook pro (10.9.5) and I am not able to download.
File → 3D Warehouse → Get Models…
Search ‘pvc pipe’
Select ‘PVC Sailboat’ by Teddy Bear
nothing happens
I restarted the mac, repeated the above, same behavior. This is all within the Sketchup app, so I am not aware if Chrome, Firefox etc. issues apply. My default browser is Chrome.
Cursor should change to Move cursor to place… It worked for me, too. Try the same thing in a browser - sounds like some issue on your network if that doesn’t work.