Error when I try to insert a new form

I'm using Dreamweaver CC on a Mac (OS X Mountain Lion).
When I try and use the "Insert New Form" option, I just get an error message (see attached).
Then, the window doesn't load up, so I press the ESC key, and I get the second error message (see attached).
I've already deleted the Dreamweaver Cache file from the folder in the other support tutorial... didn't do anything.
Any advice would be very gratefully received...
Thanks...

What version of Data Bridge do you have installed?

Make sure to have the latest version that is available from your account installed.

also, do you have any other WebAssist Extensions installed?

Before installing Data Bridge, did you install the Deprecated Server Behaviors extension?:
http://www.webassist.com/tutorials/Server-behaviors-for-Dreamweaver-Creative-Cloud

Yes, I have the latest version - it was the Dreamweaver CC version that was available on the page immediately after the successful payment.
Yes, I have installed the deprecated server behaviors extension.
No, I don't have any other WebAssist products installed, and never have had - this is my first experience of purchasing one.

Thanks very much - your assistance here is very much appreciated.

When you deleted the cache file, was Dreamweaver closed?

both DW and the extension manager must be closed when you delete the cache file.

try restarting the computer, then delete the cache.

if you continue to have problems, see the PM

Hi,
Tried that, but no joy - same problem

See PM

Have posted in PM.

try step 12 of the Dreamweaver troubleshooting menu to recreate the users configuration folder:
http://helpx.adobe.com/dreamweaver/kb/troubleshoot-javascript-errors-dreamweaver-cs4.html#main_user_config

then reinstall Data Bridge.