Please provide more details. Winodws or Mac? Have you updated EM to the latest version 7.2.1? What do you mean by "Stopped working"? Did it hang up during launch? Did nothing happen when you launch it? Did error message pop up? Could you attach a screenshot?
I can certainly give you details relating to my problem. I downloaded jsp support for Dreamweaver. I am attempting to install the extension and Adobe Extension Manager CC instantly crashes, providing the popup message stating,
"Adobe Extension Manager CC has stopped working.
A problem caused the program to stop working correctly. Please close the program.
->Close the program"
Pretty vague if you ask me, but quite typical for Adobe.