Heres a fix that worked for me
I had the same problem, and here how you can fix it.
Go to your hidden app directory and find webassit. You will find a directory just like you have listed in your dialouge box in your message. Copy all files out of your shared webassist folder and put a copy of all of them in the C: program folders. Look at your dialouge box and that is the path that you will need to copy all too.
Delete the .dat file in the configuration folder.
Relaunch dreamweaver and you will now be able to register all the software, it took me 2 days to figure this out. All mine are now working. And I had the same thing.
I would not delete your configuration folder, it did not help.