How do I regain access to Font Book? It opens, hangs, then requires Force Quit I just purchased a new MacBook Pro and migrated everything over from the old one. I had imagined that it was the old one that was preventing me from being able use Font Book (Font Book.app); it’s not that.

When I attempt to open it on the new machine, looks like it is going to work for about five seconds, then becomes completely non–responsive, including the spinning wait cursor, until I use Force Quit.

So far I have tried deleting 


~/Library/Preferences/com.apple.FontBook.plist,
~/Library/Preferences/Saved Application State/com.apple.FontBook.savedState, and
~/Library/Fonts,


and then rebooting, but to no avail.
Make a backup of /Users/YOUR_USERNAME/Library/FontCollections, and then delete that folder. Most likely, it's a corrupt font collection. Then, recreate the folder, and add each one back if you really want to investigate. 

Otherwise, just delete the collections and start over.