Font Book does not Install all fonts My Mac decided to delete all but 19 fonts, which is fairly annoying. It didn't really delete them, as in I still have the original files in the /Library/Fonts folder, but they've disappeared from Font Book, so I can't use them. 

Now, Apple says that you can select a folder to install all fonts in that folder, but when I try that, the spinning wheel (not the beach ball) comes up in the lower right hand corner for a few seconds and then leaves, without installing any fonts. The same thing happens if I use the + sign in the menu bar, select multiple, or if I try validating and then installing (actually, that installs one font). 

Is there any way to mass-install these fonts or will I have to install them one by one?

System info: Mac OS X 10.5.8 running Font Book 2.1 (123).
I'll bet you have a font corruption problem.


Split the uninstalled fonts into two groups.
Import the first group.
Check to see if they imported successfully.

If yes, you know the problem is in the second group, so go to step #1.
If no, the second group might be okay, so try importing that.



And so on.

You should be able to narrow down the problem without having to import each font one at a time. But my guess is that one or more of your fonts is corrupted.