People have reported getting an error message when clicking on the Type tool in PhotoShop. The error message says, “Could not complete your request because of a program error.”
The Adobe installer for Photoshop or any Creative Suite installs a large number of Adobe Open Type fonts in /Library/Fonts. Because all those fonts are in one of the Mac OS X Fonts folders, they’re active all the time. People who use font management software like FontExplorer or Suitcase usually prefer to clear those fonts from the Mac OS X Fonts folder and import them into their font management program instead. That way they can activate those fonts when needed, and avoid having them clog the Fonts menu at other times.
Photoshop has certain required fonts without which the Type tool won’t work. Adobe knowledge base article 84363 deals with troubleshooting font issues in PhotoShop CS5, and it lists Photoshop’s required fonts. They are:
Required Fonts in Photoshop CS5
As long as those fonts are made active in your font management software or are in one of the Mac OS X Fonts folders, the Type tool should work.