Adding my comment from another thread to see if it helps anyone.
Had this same issue and managed to get there in the end through Sky support with the following (fairly long) steps:
To try and resolve your issue, we'll need to fully uninstall Sky Go and it's associated files. Before we can do that, we need to make sure the Application is closed and has stopped it's background processes. To do this:
1. On your keyboard, press 'Ctrl', 'Alt' and 'Delete' at the same time to bring up Task Manager.
2. Go to the 'Processes' section.
3. Find 'CiscoVideoGuardMonitor.exe', then click 'End Process'. You might have to click 'End Process' again if prompted to do so.
You'll now be able to uninstall the Sky Go Application and the Cisco Video Guard Player. To do this:
1. Click the Start button, then select 'Control Panel'.
2. Click 'Programmes and Features' or 'Uninstall a program' (whichever shows).
3. Now, uninstall the ‘Cisco VideoGuard Player’ and ‘Sky Go’.
Finally, we need to delete all the remaining hidden files/folders associated with the App, but first, you’ll need to make sure you can view any hidden files. To do this:
1. Click the Start button, then select 'Computer'.
2. Select 'Organise', then 'Folder and search options'.
3. Click the 'View' tab, make sure the box next to 'Show hidden files, folders and drives' is ticked, then press 'OK' to confirm.
Finally, we need to delete all the remaining hidden files/folders associated with the App, but first, you’ll need to make sure you can view any hidden files. To do this:
1. Right click the Windows button then click 'File Explorer'.
2. Click the 'View' tab, then in the Show/Hide section tick 'Hidden items'.
And to delete the remaining folders:
1. Click the Start button then select 'Computer'.
2. Open the '(C
Drive', select 'Users' then your username.
Select 'AppData' then 'Local', then select 'Cisco'.
3. Delete the VideoGuardPlayer folder.
4. Open the '(C Drive', select 'Users' then your username. Select 'AppData' then 'LocalLow', then select 'Cisco'.
5. Delete the VideoGuardPlayer folder.
6. Open the '(C Drive, select 'Users' then your username. Select 'AppData' then 'Roaming'.
7. Delete the Sky folder and the Sky Go folder.
5. Open the Downloads folder, then delete all ‘SkyGoInstaller’ files.
Once you’re done, empty your Recycle Bin.
To see if the issue is now resolved, we need to reinstall Sky Go and test it.
You can download it again on your device at this address: www.sky.com/watch/sky-go/windows
Steps if still encountering an issue:
1.Right click on Sky Go Short cut.
2.Select 'Properties' then 'Compatibility.'
3.Uncheck box 'Run this program in compatibility mode for' and press OK.
4.Relaunch Sky Go app then retest if white screen hangs on login box restart PC to fix
Hope this helps someone!