For privacy reasons, OS X does not allow third-party applications (such as TextExpander) to log keystrokes, unless access for assistive devices is turned on.
In OS X 10.8 and earlier:
- Go to the System Preferences and activate the Universal Access preference pane (the one with the little person in front of a blue background). Once you’re there, check the box “Enable for assistive devices.”
In OS X 10.9:
- Go to System Preferences -> Security & Privacy -> Privacy -> Accessibility -> TextExpander.