This was driving me crazy and then I figured it out … lets assume you need to edit and existing vpn connection or maybe you imported a new ovpn file and need to edit it, but you can’t because its 2020 and everything else is going wrong so what the hell. This is how to fix it ….
And look for the tab that shows “ca certificate” and “user certificate” and right under it shows “user private key” and it is blank.
So click on the folder and browse to ~/.cert/nm-openvpn/profile_name-key.pem and select it.
This will allow you to edit and save exactly 1 time … you have to do this each time you want to make changes. How’s that for a cluster fuck?