The problem is DW CS 6 dose not have enough memory to create the records sets, if you have a ton of extension install you will face this issue no matter what, especially if you Bootstrap 3 by dmxzone install or any Bootstrap install that will do it, these extension required lots of computer recourse and they will crash dw6 or dw6 will try to adjust be not rendering some functionality.
Solution:
go to your conflagration folder : C:\Users\Username\AppData\Roaming\Adobe\Dreamweaver CS6\en_US
Make a copy so you have "Configuration - Copy"
create the a folder call it "Configuration" and launch DW CS6, try to make your connection to a database see if everything is normal,
I am sure its all because today extensions who really asking for a lot of Memory
