Installing zxp Extension fails - Extension manager cant update data base

Cant get the new zxp extensions to install in DW CC. When double clicked the extension manager opens and the process begins but at around 2 minutes in a dialogue box appears saying that "Failed to update database. The extension will not be installed". Have tried this with Data Bridge, Ecart and Free Tools so far with the same result. However design extender did install but nothing from that suite works in DW
How do I fix this please?

Looks like this is a bug with the CC Extension Manager on Mac OS.

If you open DW, you should see that the extension is actually installed. I tested with eCart and got the same error, but opening DW, eCart was under the Insert -> WebAssist menu and was functional.

This issue is happening for other extensions as well, not just ours, there are a few threads about it on the Adobe forums, the Project 7 Forums, and DMX Zone forums.

Thanks Jason for looking at this.

Initially I found the extension in the menu as well but nothing worked, however after opening and closing DW several times it worked - in fact all of the failed installs were there and after activation worked, well they open the wizards but I have yet to fully test functionality.

A strange thing though is that only Design Extender appears in the CC extension manager - I guess that is part of the Adobe bug?