The strangest thing happened overnight. I try to debug an app from Android Studio to Genymotion. I see Gradle build finishing, but the app is never deployed. Thereafter the debug button gets disabled. The same story occurs with the run button. And neither SHIFT+F9 nor SHIFT+F10 work. Has anyone faced this problem as well?
I am using Android Studio 1.5 RC1 and latest Genymotion
If the above solution doesn't work, just try re-installing Android Studio. And when installing, make sure HAXM is installed properly. Use this link for reference. I used to have the same issue too.