Problems with windows 8 64 bits
I have the same problem as you. I had this problem with windows 8 64 bits and dreamweaver cs6 too.
I solved this running dreamweaver cs6 and extension mamager cs6 as administrador, and its runs.
This time i can´t run extension manager as administrador because the cc version crashs :(. I think that webassist extension have problems with windows 8, because i have a labtop and i have the same problems too, and i tried even formating the computer.
maybe if you try running it as administrator works for you