These errors are usually due to internet connection issues or geo-location issues - where your location is being reported wrongly or you are outside the UK.
Things to try to resolve an Error Code 3 issue on iOS devices:
- First make sure you are still connected to the Internet and the connection is stable.
- That you are in the UK - STV Player and Player+ are not available outside the UK.
- Make sure you are not using a VPN to connect to the internet - if so you should turn this off and try to watch the content again. You can check this by going to Settings -> General -> VPN.
- Ensure that you have allowed STV Player to use your location - Settings -> STV Player -> Location
- If you have access to a different WiFi network then try connection via that one to see if the issue is with the current WiFi and it's location information. Or use an online service such as whatismyipaddress.com to check where your ISP is locating you.