As you are using a Mac, is it safe to assume you are also using Safari? If so, this browser does have a setting that will shut down plugins. You can follow the steps below to fix this:
*In The Upper Left Of The Mac; Click Safari and go into "Preferences"
*Once Preferences Has Popped Up, Go Into "Advanced"
*You Should See A Check Box That Says "Stop Plugins To Save Power"; ensure this box is empty so that the setting is inactive.
*Restart Safari; you will want to make sure that Safari is fully closed and not running in the background.
Once you have completed those steps, try and connect again. You should have no further issues from there.
I hope this helps!
Sling Media Technical Support