Yes, this is a compatibility issue with Mac Yosemite, we have just finished updates to address compatibility with DW CC 2014.1, so are now going to start working on updates for Yosemite.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.