(Sorry, that sounds like the bad old days of Windows, but macOS sometimes gets itself into a situation that only restarting will fix.)
Try restarting your computer before installing.
#Download tunnelblick install
If the above are all good and you can't still install, here are some things to try before trying to install again: It may take a few seconds, but the process should disappear from the list.
If there is a process named "Tunnelblick", click the "X" to quit it, then click "Force Quit".Click on the "Process Name" column to sort the list of processes by name.Launch /Applications/Utilities/Activity Monitor.If you are unable to install Tunnelblick because it says a VPN is active, try the following: If you are installing Tunnelblick inside a virtual machine, are you installing from a copy of Tunnelblick that is stored on the virtual machine's startup volume (for example, on the VM's Desktop)?.Are you installing from a copy of Tunnelblick that is stored on your startup volume (for example, on your Desktop)?.Did you download a version of Tunnelblick that is appropriate for your version of macOS? New versions of macOS use the latest versions of Tunnelblick, but older versions of macOS or OS X require an older version of Tunnelblick from the Deprecated Downloads page.Did you download Tunnelblick from the official Downloads page?.If you are unable to install Tunnelblick, here are some things to check: