It might be worth a complete uninstall:
Uninstall the Sky Go app and then go to 'C:\Users\[your user name]\AppData\Roaming (ensure hidden files/folders are visible) and delete the following folders:
Sky
Sky Go
And if it is present (it might not be) the Cisco and/or Synamedia folder in App\Data\LocalLow.
Empty your recycle bin.
Reboot your PC and then download and install the Sky Go app again via here: