instant run worked for me and I don't know why it stopped: I see the thunderbolt icon of the instance run but when I click it, a popup appears :
"Restart App? The app is already running. Would you like to kill it and restart the session?" the available options are "restart app"\ "cancel"
when restart popup is shown : "Instant Run is disabled: variant 'debug' uses an unsupported feature (e.g. ProGuard)"
(I've tried to comment progourd in gradle- didn't help)
what am I missing?