If you're running After Effects CS6 (11.0), the After Effects CC (12.0.1) update is not relevant to you.
To install the After Effects CS6 (11.0.3) update, do the following:
1. Restart your computer.
2. Open Adobe Bridge and no other applications.
3. In Bridge, choose Help > Updates.
If that doesn't work, uninstall After Effects CS6, restart your computer, reinstall After Effects CS6 (11.0.0), and then do the three steps above again.