Firstly, ensure that you are using L2TP VPN type. If you are using PPTP, please setup a new L2TP client using this guide.
If you are getting a Netflix proxy error, ensure that you have the following entered in the 'DNS Servers' box (under 'show advanced options). 220.127.116.11
If you are unable to connect using Android 6 or above:
- Tap the "Settings" icon next to your VPN profile. Select "Show advanced options" and scroll down to the bottom. If the option "Backward compatible mode" exists, enable it and reconnect the VPN.