Q: iMovie 2014 can't find old iMovie files to update

I have old iMovie projects dating back to 2006 on an external drive that I didn't get around to updating till now.  When I try to update these files iMovie 2014 cannot find them.  I have tried Update projects and events from previous versions of iMovie in iMovie (2014) - Apple Support but I can't seem to find a way to make it work. 

Also note I have new projects that already exist on my computers HD.  Would I be able to keep projects on both the external and internal HD?  I don't have space to keep all my movies on the internal.

Any help would be great

Thanks