Knowledgebase

It means that another software is using the tun/tap interface.

Please do the following:

Enter "keststat" in your terminal.

It will give you a list of all tun/tap interfaces( they contain the "tun" in their name)

After that you should deactivate this interfaces. For example:

For kext com.viscosityvpn.Viscosity.tun you should do:

"sudo kextunload -b com.viscosityvpn.Viscosity.tun" in your terminal.