Windows 10 "Add a VPN connection" stuck on save

Since updating to Windows 10, we haven't been able to connect using our VPN anymore.

Every time we try to add it using the new interface it stays stuck on save. The old interface just directs us to the new one.

As you can see from the screenshot, the save turns gray and just stays that way.

The VPN uses PPTP (MS-CHAPv2) and is working fine on older versions of Windows, Android and Linux.

Any suggestions on how to fix this or an alternative client we could use?

I tried adding the VPN using Powershell:

Add-VpnConnection -Name "Work VPN" -ServerAddress "8.8.8.8" -TunnelType Pptp -EncryptionLevel Required -AuthenticationMethod MSChapv2 -SplitTunneling -RememberCredential -PassThru

This returned "The system could not update the phone book file". That's how i stumbled on the solution, a recently updated Mcafee rule "Protect phonebook files from password and email address stealers" was preventing me from adding new VPN connections.