After re-installing DW CC 2014, it installed the Deprecated Panel Support extension automatically as I'd added at as an add on so it synced itself.
Then I re-installed DB using the Extension Manager (CC).
Its working in CC - after opening a page the installer ran. And when i tried to test it, it accepted the serial number OK.
I noticed that the Web Assist menu appeared across the top before the WA installer ran.
But it still isn't doing anything in DW CC 2014, and there is no Web Assist menu across the top. (Not sure if it would appear before the installer runs as it seemed to with CC).
So not sure what else to try?