SAFARI 12 UPDATE

lkrupp wrote:

I don’t have Silverlight or Flash installed and Safari 12 plays Netflix content just fine on my iMac. No problem playing Amazon Prime video either. So I don’t know what’s going on with some people’s installations.

Macs before early 2011 require Microsoft Silverlight to view content as for whatever reason Safari doesn't work to view HTML5 content on them (perhaps for performance/resolution reasons.)

However Google Chrome does work to view HTML5 content on those systems and is listed as a viable alternative in Netflix's FAQ.

There are many posts about this, but to sum it up, if you have a 2011 or earlier Mac that does not have a Sandy Bridge CPU, it does not have hardware h.264 decoding built-in, so Safari's HTML5 implementation will not work. Chrome & Firefox use software decoding, and are limited to 720p. Apple blocked plugins in Safari 12, which is why Silverlight doesn't work. At this time, there is no way to get Netflix, etc. working in Safari, at all. Unlikely there will be a "fix" with Silverlight reaching end of life, and Apple moving forward and not looking back as they always do.

Silverlight is one of several NPAPI plugins that are no longer supported, and Apple can't list each and every one that used to work.

Note that though Safari can't support 1080p H.264 decoding, both Chrome and Firefox support HTML5 decoding in software, albeit at a maximum resolution of 720p.

That is true, and as I (and Netflix) have stated, if you have a pre-2011 Mac you need to use Chrome or Firefox.

Apple removed support for NPAPI plug-ins, which Silverlight is. If you can you should try activating HTML5. Unfortunately for me my home entertainment system is run on a 2010 Mac-mini, which doesn't support HTML5.

I don't think SilverLight is the main issue here. Chrome and Firefox use the software API for html5 so these browsers work; albeit, at a reduced resolution. Apple chose to make Safari 12 only use hardware for html5. That's what has really left Safari unusable on machines older than 2011. When I check the specs for Mojave, my mid-2010 Mac Pro qualifies because I've upgraded to a Metal compatible graphics card. The old machine still doesn't qualify for Netflix or anything that requires html5 using Safari.

Running Google Chrome to view content should be a viable workaround for anyone experiencing this issue.

Although the OP and most here are concerned with Amazon video and Netflex viewing, the OP was also concerned about running silverlight. There are other websites based on Silverlight that don't use video, there are two that I use, one a city map site, one a stock charting site, and HTML 5 is not a solution. Moving from SilverLight does not seem to be a priority for them. Seems SeaMonkey (free) and iCab ($10) will still run the SilverLight extension.

So far, what I've gleaned is if you have a Mac prior to 2011, HTML5 and Safari will not play Netflix or Amazon Prime Video, which is why you still need Silverlining. If you have a newer Mac than say my mid-2010 Mac Pro, that may be why it's working for you. Let us know. BTW, Chrome does use HTML5 acceptably on my Mac Pro.

According to this post on the discussions, apparently, if you have a machine (in most cases) after 2010, it safari uses hardware decoding to decode HTML5, so silverlight isn't even being engaged.

If you are using an old version of Chrome or Firefox, these browsers will use silverlight to decode.

I conclude this because I have two MB pro's (a 2010 and a mid 2012), and they are identically configured. The 2010 cannot see Netflix using Safari but the 2012 model can. The 2012 is probably using hardware decoding to watch HTML 5, but the 2010 does not have the proper hardware in it to do that, so Netflix keeps thinking you've not properly got Silverlight installed.

Not really looking forward to buying a new laptop just to watch Netflix, but then again, we run a business off an eight year old laptop, and I think that's pretty impressive.

To be honest, once again, any vendor relying upon Silverlight should be taken to task as Microsoft discontinued development of it in 2013 and told media companies to stop using it in 2015.

Apple's developer page for Safari 12 put it more succinctly:

Removed support for running legacy NPAPI plug-ins other than Adobe Flash.

Apple probably should have made a bigger deal about this, but given every other web browser available on Macs hasn't supported NPAPI since 2017, this wasn't Apple being non-standard or proprietary.

As has been pointed out a number of times now even Microsoft has bailed on Silverlight. They no longer develop or support it. It’s a dead format so it says more about the websites that still use it than browsers that don’t. The major browsers have all deprecated support for traditional plugins in favor of better, more secure technology.

Some people have posted they were able to get it to work by reinstalling Silverlight.

I have the same issue. In Amazon Prime, it states, "unsupported plugin." From what I can gather through my research, Safari 12.0 is the culprit. Apparently, Apple is enforcing its plugin policy of only accepting plugins listed in its Safari Extensions box. Silverlight is not in there, which is what Amazon Prime says we need. However, it is supposed to work with HTML5 also. Maybe somewhere HTML5 is turned off? I looked and could not find a way to turn it on (if it is in fact off).

I had the issue in Amazon Prime as well. I just finished reinstalling High Sierra and its updates and now have the older version of Safari back. Netflix and Amazon Prime are back. If anyone figures out how to get HTML5 to work with Netflix and Prime Video, I'm sure there are several of us who'd like to know.