Network(-1) Error is shown when the device fails to communicate with software update server.

The reason could be a connection block between the device and update server by your ISP(Internet Service Provider). 

💡 Please try a couple of things below to see if it helps.

1. Verify that you have stable internet connection to your device by opening YouTube and playing a video.
2. Clear 'Software Update' app  ( Home > Settings > Apps > Find Software Update app and clear data/cache)
3. Open the Market app and install the latest "Software Update" app and try the update again.
4. Try to connect the internet using your mobile hotspot instead of home network.
5. Try to use VPN - Apps are available at Home > Market for download. (e.g., Express VPN, Nord VPN and etc)
   Sign up with your VPN provider, Turn on the VPN and try software update. 
6. Perform a Factory Reset  👉 How to factory reset your device

IF this doesn't answer your doubts or you want to search more information,
Please take a look at threads in our forum FORMULER FORUM Or click TAGS on the right side of this page.