Erroradb server is out of date. Killing...
adb server didn't ACK
* failed to start deamon *
If you see this error that means adb in your sdk is not in sync with any other adb you are trying to access. That adb may be of some 3rd part emulator like Genymotion.
To sync them, copy adb from sdk/platform-tools and replace the existing adb in Genymotion with this one. Launch emulator again and try same command in a new command prompt.
It should work.