This error is usually shown after uninstalling other VPN clients that uses openVPN. You may follow the instructions below to reinstall the TAP adapter:
1. Open the folder where proXPN is installed(default path is: C:\Program Files (x86)\proXPN or C:\Program Files\proXPN)
2. Go to the "bin" folder and look for addtap.bat
3. Right click the file then select "Run as administrator"
4. The TAP driver will install, wait for a few minutes. You should see "Drivers installed successfully." once the adapter has been successfully installed. Press any key to close the command prompt window.
5. Restart the proXPN app then check if you will be able to connect to the VPN.
If that doesn’t help, you may need to reset winsock:
Type Cmd in the Start Search text box and press Ctrl-Shift-Enter (keyboard shortcut to run Command Prompt as Administrator). Click Continue to allow elevation request. 3. Type netsh winsock reset in the Command Prompt shell, and then press the Enter key.
Also, open Control Panel, Network and Internet→Network and Sharing Center. click Change adapter settings on the left, then right click TAP-Windows adapter, select disable; after disabling it, then select Enable. After TAP-Windows adapter is reset (by disabling and then enabling it), restart proXPN and connect.