Comment 5 for bug 1718931

Yeah, I keep getting the "vpn-connection[...]: Failed to request VPN secrets #3: No agents were available for this request." error message in my syslog. I found, however, that THIS worked for me: All you have to do is go Dash->VPN->VPN Settings->connection_name_here->Identity->Password->"Store for all users" and bingo problem solved. If nm-connection-editor says that you can't save the connection (the save box is grayed out), then...just forget the network and set up the connection again (worked for me at least). Once you have checked said auto-connect box with nm-connection-editor and ensured that the VPN password is set to "Store for all users," both the primary connection AND the VPN will start successfully at the same time. See my post at https://askubuntu.com/questions/967408/how-to-automatically-connect-to-vpn-in-ubuntu-17-10/967415#967415