To resolve the issue, follow these steps:
- Click the Finder icon in the Dock.
- From the File menu, choose Find.
- Type "Safari.app" in the File Name Contains field.
- Click Search.
Note: The resulting files will be named simply "Safari", since the ".app" suffix is hidden by default.
- One at a time, double-click the copies of Safari that are found until you find the one that works.
- Using the copy that works, download Safari again from its website (http://www.apple.com/safari/).
- Drag all copies of Safari.app to the Trash.
- Reinstall Safari using the Installer you just downloaded.