If you have corrupt fonts or install too many fonts in OS X you may find that applications load slowly or that menus can’t load properly. To fix, you may find the easiest path, rather than attempting to remember what the last font you used was, is to restore OS X to the default set of fonts installed with the OS installation. To do so, check out fontrestore. This handy little command uses the fontmover tool to move fonts from in /Library/Fonts, /System/Library/Fonts, and ~/Library/Fonts and to directories that say (Removed) at the end of the name. To run, simply run fontrestore with the default option:
You’ll then be prompted to enter an admin password. Provide the appropriate password and then click on the Restore button. Then look and your fonts should be restored to a pristine working environment.