I am currently getting my free month on Amazon Prime and am eager to watch All or Nothing. I have an imac 27" with 12gb RAM. I'm using OS High Sierra 10.13 and the latest update of Safari as my browser and am using a 150 - 200 Mb (which is what i get according to Ookla) download broadband speed. So I think my system requirements are fine. When I try to stream it all in get is a black screen with "Unsupported Plugin" Safari/system preferences/websites has amazon as Autoplay On. Again in preferences the only listed Plugin is Flash player but I believe Amazon uses an HTML5 Plugin automatically which should be avaialble in my version of Safari. I've tried both options of flax player on and off - nothing. I tried downloading Silverlight as an alternative Plugin but the system doesn't recognise it in Safari/system preferences/plug in - so it's downloaded but seems to only be available as a application. It just won't play - anyone any ideas?