Is there a terminal command to restart an application?
You're using cs6 that uses Java 6 and Yosemite I believe is Java 8. You could try installing java 6 but it isn't supported and neither is DWcs6. Unfortunately that's the way of it. I don't know if you have a creative cloud account. They provide all updates. If not you could try the Java route or another FTP client. :/
Edit::
Correction. I forgot since o have to install Java for dev purposes. Yosemite doesn't come stock with it. BUT I found this. It may help. http://support.apple.com/kb/DL1572?viewlocale=en_US&amp;locale=en_US