Just received from Adobe...
And I just received this email from Adobe, this morning. It makes my Macbook run a bit slower, but seems to make all the extensions work (for what it's worth):
Please follow the below steps to install the extensions to Dreamweaver CC 2015:
1) Open the creative cloud application, and sign out of the same (click on the gear on right top> preferences> sign out)
2) Download and run the uninstaller for the creative cloud application: https://helpx.adobe.com/creative-cloud/help/uninstall-creative-cloud-desktop-app.html
3) Install the latest version of the creative cloud application from the below link: https://creative.adobe.com/products/download/creative-cloud
4) Uninstall the Creative Cloud point product (Dreamweaver or Flash Pro, in our case) and reinstall the software. Do not open it right now. Also, remove the previous creative cloud versions of the application, if any installed on the machine. Open the Home tab in the creative cloud application, you should be able to see acquired extensions start installing automatically, if you don’t see them installing after few minutes:
a) Go to https://creative.adobe.com/addons/my_addons
b) Start installing by clicking on Install button. ( if already installed and you are not seeing the extension in product , click on the remove button andclick on install again)
5) Open Dreamweaver / Flash Pro and see if the extensions appear as intended Please let me know if this works, or you need any further assistance.