Hi

What happens when you try to watch Sky on Firefox?

This may be your problem,

Firefox v52+ disables all plugins except for Flash Why do Java, Silverlight, Adobe Acrobat and other plugins no longer work? {web link}

Install Older Version Of Firefox {web link} Be sure to read everything here.

If you still want to downgrade, look under; I still want to downgrade. Click the Directory of other versions and languages link. Look for the directory of the version that you want. But, remember that old versions may have security issues.

You should also check out Firefox; Extended Support Release {web link} ESR Notes System Requirements

Sky Go uses the Silverlight plugin, therefor you should follow FredMcD's advice and switch to the ESR version of Firefox, that still supports the Silverlight plugin.

You can download the ESR Firefox version here :

https://www.mozilla.org/firefox/organizations/all/

Windows Users: When you get to the ESR installer list, you'll notice at least two different downloads for Windows: • Windows installer is the standard version for Windows that runs on both 32-bit and 64-bit Windows Vista through 10 (and 32-bit XP), the best choice for most users. • Windows 64-bit installer ONLY runs the Flash and Silverlight plugins.