Please try to run EM as administrator firstly.
1. Run "/Applications/Utilities/Terminal.app".
2. Input the following command then press "Return" key. Don't miss the double quotation marks.
sudo "/Applications/Adobe Extension Manager CC/Adobe Extension Manager CC.app/Contents/MacOS/Adobe Extension Manager CC"
3. Input password of administrative user then press "Return" key.
If it works, you can try to run EM in normal way.