There is little chance that you can edit the sample configuration file to get your VPN working. That's not how it works -- the two ends of a VPN need to work together and need to have coordinated configurations.
Your best bet would be to contact your VPN service provider -- the organization that provides the VPN to you in the first place.
But if you don't have that, because someone set up your VPN to work within your organization, for example, and you aren't using an outside service, your could try to restore Tunnelblick's settings and configuration information from backups (for example, a Time Machine backup). If you have a backup, you can restore the Tunnelblick configuration information (which is what is missing) by restoring the following:
- /Library/Application Support/Tunnelblick
- ~/Library/Application Support/Tunnelblick
- ~/Library/Preferences/net.tunnelblick.tunnelblick.plist
(In Time Machine, you would look at different backups, going back in time starting from just before the problem appeared. You'd look in /Library/Application Support and, when you find it, restore that, along with the other folder and file from the same backup date and time.
Another approach would be to find out who set up your VPN in the first place and have them set it up on the Mac.
Another approach, if you have other computers that connect to the VPN, you could try to find their "OpenVPN configuration file(s)", copy the file(s), and install them on the Mac. That might work, or it might not, depending on exactly what is in the file(s). (For example, the file(s) might refer to other files, and you would need to copy those files to the Mac, too.) I don't know where to find OpenVPN configuration files on a Windows or Linux computers; you could ask OpenVPN experts about that (see our
Support page for links).