it sounds like you installed an updated version without first uninstalling the previous version.
any time you install an update, you must first uninstall the previous version from the extension manager. installing a new version over the existing version will corrupt the configuration folder.
you can rename the configuration folder to get Dreamweaver back to a freshly installed state.
see the common installation issues pdf for details on locating the Configuration folder:
rename the configuration folder to configuration_bak.
when you open the extension manager, a new fresh configuration folder will be created.
you should then remove all the extensions, the install the latest versions.