I had an error yesterday when using Safari 8. It didn't matter if Silverlight was installed or not, Netflix was unable to play video. It wasn't my internet because Chrome and Firefox were ok. Today I uninstalled Silverlight and tried again and it works now, using HTML5 of course. Maybe it was a temporary glitch in Netflix, you should try again today.
Just tried removing Silverlight completely and re-installing and still no go. Getting the same error.