Q: OSX Update 10.10.3 installed, iMovie 9.0.9 now can't access source clips

I found that movie clips originating in iPhoto had little yellow triangles which stated that the media files were unavailable.  Yet when I tracked down the filenames in the Finder, they appeared to be right where they belonged.  iMovie was referring to these files using the base directory "~/Pictures/iPhoto Library".  However, when I navigated to my Pictures directory using Terminal and typed "ls", I found that the iPhoto library was actually named "iPhoto Library.migratedphotolibrary".

Aha!  So the iPhoto library was renamed when I upgraded to the new Photos App, but Finder hides the ".migratedphotolibrary" portion so it looks the same.

I considered renaming it back to "iPhoto Library" but was unsure if that would break something else.  Therefore, I created a symlink in the Pictures directory which redirects "iPhoto Library" to "iPhoto Library.migratedphotolibrary".  Worked like a charm.  Here is what you do:

1. Open the Terminal App.
2. Enter the command: cd ~/Pictures
3. Just to confirm you're in the right place, enter the command: ls
4. Enter the command (be sure you get the quotes right): ln -s "iPhoto Library.migratedphotolibrary" "iPhoto Library"

Good luck!