1. If you have two or more VPN connections set up on your computer, ensure that only one is running and disconnect all other ones.
2. Check for any firewall and antivirus programs that may stop access to the VPN ports. Temporarily disable them to determine if they are the cause.
- TCP Port 1723 and GRE Protocol 47 must be opened/enabled for PPTP VPN connection
- Some routers require PPTP pass-through enabled in the router
3. Try standard troubleshooting steps:
Reboot the computer
Delete and re-configure the VPN set up
- Test the VPN on another computer/device on the same network. If it does not work, your network is stopping the VPN access.
- Test the VPN on another network using the same device. If it does not work, your device has security software stopping the VPN access.