Possible reasons:
- Check Login credentials
- Check mobile/tab device is connected to Wi-Fi/Internet.
- Check if Server is Down or working.
- Try Restarting the Server.
- Check it IT dept. staff for change in IP address of server.
Error messages:
Server not found - Enter correct Server URL address (check with IT support staff) or Server is down.
invalid credentials - User name or password is wrong. If forgotten, contact IT support staff.