- Choose System Preferences… from the menu
- Choose Security & Privacy from the View menu of System Preferences
- If locked, click the lock icon at the bottom left and enter your admin password
- Click Accessibility in the list on the left
- Check both TextExpander and TextExpander Helper in the list on the right
- Close System Preferences
- Launch TextExpander
For more visual instructions see our blog post. For problems in Yosemite where TextExpander Helper does not appear in the Accessibility list, see this article.