In some situations where OS/X tries to deal with changes to it's Internet connection it leaves the network interface in an errored state. This prevents OpenVPN from starting.
Quick & dirty solution:
- Reboot your computer.
Cleaner but more complicated solution:
- Open a Terminal window. (Found in Applications -> Utilities.)
- Enter the following commands:
- sudo ifconfig en1 down
- sudo route flush
- sudo ifconfig en1 up
- Please make sure to replace en1 with your actual Internet interface.
- If you don't know which en interface is your Internet interface you can do a:
- sudo ifconfig
- To get an overview and figure our which en interface is your Internet interface.
Above document is written for users of 12vpn.com but may apply to users of other VPN's.