Resolved: "The IPSec Shared Secret is missing"
I just resolved this issue.
I manage the VPN at work and was trying to connect via ipad then I got the message
"The IPSec Shared Secret is missing. Please verify your settings and try again."
If your environment is a Microsoft VPN (Routing and Remote Access) or using PPTP...
The solution is:
1. Delete existing VPN that didn't work.
2. Create new VPN and do NOT add anything on the L2TP tab.
3. Click on the PPTP Tab and enter the information here - your need description, server, account - I leave passwrod to Ask Every time.
4. All other settings - leave the defaults.
This worked for me.