We have detected an issue for the new iOS update and our engineering is working on a fix right now.
Meanwhile there is a possible work around that might help, you can go to watch.slingbox.com from either
browser- Chrome, Internet Explorer or Firefox. Which may lead you to access your sling account.
We will keep you posted as soon as we submit the updated app on Slingbox.com.
The fix will require an update to the app.
Thank you !
Sling Media Support
When do you expect this to be fixed. I am also experiencing the same thing. I have never had a problem with my sling box, and now that i updated my OS to Sierra, all i get is the following error "safari can't open "spb-sling-player://" because MAC OS doesn't recognize internet address starting with "SPB-sling-player"