D6200 Port Forwarding | VPN question!

I just tried to open the following ports on a Netgear D6200:

VPN-PPTP TCP 1723
VPN-L2TP UDP 1701
VPN-IPSEC UDP 500

I selected the pre-configured PPTP, L2TP from the drop down menu and they added okay. The pre-configured IPSEC on the other hand wouldn't add, the router stated the following:

The specified port(s) are being used by other configurations. Please check your configurations of USB Readyshare, Remote Management, Port forwarding, Port Triggering, UPnP Port Mapping table, RIP, and Internet connection type

I've navigated to each of the suggested router configurations (USB Readyshare, Remote Management, Port forwarding, Port Triggering, UPnP Port Mapping table, RIP, and Internet connection type) and I can see no setting for VPN-IPSEC UDP 500 showing as being in use.


Also, the same ports that I could actually apply as mentioned above still wont open either, to make matter worst.


Any ideas please?