Xcode 6.3 freezes/hangs after opening XIB file

After upgrading to Xcode 6.3 (release version), Xcode now freeze every time I open a XIB/Storyboard file that includes an IB_DESIGNABLE view that uses a custom font for any projects and includes a custom font (not necessarily to have reference to that font in that XIB/Storyboard). The freeze occurs after opening the .xib file and then attempting to switch to any other file. Xcode hangs and must be force quit.

I have opened a bug report with Apple. (Bug 20483867).

Right now, I have two work arounds.

1. Download and use Xcode 6.2 from Apple.
2. Remove the IB_DESIGNABLE tags from the custom view header files.

This is likely an Apple bug, but does anyone have a better work around or solution?

Xcode 6.3.1 fixes the problem with custom fonts and IB_DESIGNABLE views in a Storyboard. Update via the Mac App Store, and you should be good.