I had to completely uninstall all extensions after the obvious steps i.e. deleting the .dat file etc, then I still had multiple errors on start up of Dreamweaver, so I had to uninstall and re-install Dreamweaver.
The problem seems to occur when the mxp installation file, and therefore, causes various problems when attempting to install the extensions again, Adobe Extension Manager can not complete the installation and crashes, when a reboot is attempted the Anti virus automatically quarantines the file.
I guess the reason this post has not been answered is due to the Thanksgiving celebrations in the US, so my advice would be to await the return of the web assist support team.
Fingers crossed this can be resolved quickly and efficiently, I assume this is down to a incorrect virus definition with my security software, just out of interest, What Antivirus software are you using?
If you find a solution could you post back to this forum please
Thanks and take care