Please take a look at https://wiki.ubuntu.com/DebuggingNetworkManager and try to submit some logs that show NetworkManager's error message when trying to connect to the VPN.
** Changed in: network-manager-openconnect (Ubuntu) Status: New => Incomplete ** Description changed: - Connecting to VPN with openconnect through the GUI from gnome stopped - working in this version of Ubuntu. - - This has been working for years in all the Ubuntu releases and it just - stopped which is very frustrating and disappointing. + Connecting to OpenConnect VPN through the Gnome GUI stopped working in + Ubuntu 16.04. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: network-manager-openconnect 1.0.2-1build1 ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6 Uname: Linux 4.4.0-21-generic x86_64 ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: GNOME Date: Tue Apr 26 22:06:41 2016 SourcePackage: network-manager-openconnect UpgradeStatus: No upgrade log present (probably fresh install) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1575354 Title: Can't connect to VPN with openconnect through the GUI To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager-openconnect/+bug/1575354/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs