For the benefit of others, I wanted to post the steps that fixed this issue for gbrozk1:
- Open Extension Manager CS5.
- Select Dreamweaver on the left, and then remove the HTML5Pack (11.0.3 Updater) extension.
- Repair the installation of Dreamweaver using your original installation media.
- To do this, insert your original installation DVD, or double-click the downloaded DMG file, and then double-click Set-Up.app to begin the installation.
- When given choices of which products to Install/Re-install, uncheck everything except Dreamweaver. (That is, we need to be sure Dreamweaver is selected to be re-installed. Re-installing repairs the installation.)
- Follow the remaining on-screen instructions to complete the re-install/repair of Dreamweaver.
- Restart your computer.
- Install the 11.0.4 update.
Hope that helps someone!