With Dreamweaver and Extension Manager closed, try renaming the configuration directory. Then open Extension manager. All the extensions should be disabled at this point. Try removing all the extensions and open up Dreamweaver to see if the errors are resolved. If they are, close Dreamweaver, and download a fresh copy of the installer from our site and install one of the extensions and try running Dreamweaver again and that extension. Keep following this process of installing one and checking it. That way if you run into any issues, you will be able to determine which extension caused it.