Custom font doesn't appear in Interface Builder

I installed a custom font (Font awesome) into my app. I triple checked that I did everything right: the font files are included in the bundle (they appear in the "Copy Bundle Resources" build phase) and the names of the fonts appear in the Info.plist file under "Fonts provided by application".

In Interface builder, I select a Label, set the font to "Custom", then I click the Family list to select the font I want.

Once or twice, I was actually able to see the Font Awesome fonts in this list and select one. However, they no longer appear there when I create new labels in new views. I do not understand why. I've been limping along by copying a label from one of the views where it worked and pasting it into the new view, but this is tiresome.

I know the fonts are installed correctly because I can see them when I run the app.

Why are the fonts not showing up on the font list in interface builder?

Custom font doesn't appear in Interface Builder
 
 
Q