After upgrading to 8.1pro, my vpn cant work. I used F5 VPN as my vpn provided and gave me error. When I used Microsoft VPN as my connection, it keep verifying my credentials.
I am using MS-CHAPv2 and PPTP for my vpn connection.
Extra note: I am using VPN to get access to my school network. My school uses F5 VPN as their provider.