If you're getting stuck trying to download/install the browser plugin so you can use the Web player, keep an eye out for security blockage from your browser, OS or Antivirus software. The plugin typically requires explicit permission to install successfully, and the notice might be obscure or silent depending on your software and settings.
As an alternative while you're trying to figure it out, give the full Player version a shot:
It doesn't depend on the browser plugin.
Hope this helps,