Hi Andy ,
These are your possible fixes for Error 5203 :
1.Check your internet connection: Make sure your device is connected to the internet and the connection is stable.
2.Restart MT5
3.Check MT5 server: It’s possible that the server you’re trying to connect to is experiencing issues. Try connecting to a different server if possible.
4.Contact your broker: If none of the above solutions work, it would be best to get in touch with your broker. They can provide information about any server issues or maintenance that might be causing the problem.
5.Reinstall MT5: As a last resort, you might need to uninstall and reinstall MT5. This can help clear any corrupted files that might be causing the problem.