Thank you for using our Community. A lot of times, when installing an update to for the plug in, your computers anti-virus blocks it. I would recommend disabling the anti-virus for the purpose of installing the plugin update. Once the plugin installs, if the SlingPlayer starts working you can turn the anti-virus back on. If that fails, please follow the article posted below, with the anti-virus disabled, and try again:
Hope this helps!!
Sling Media Moderation Team