I recently patched my Fedora 25 system and the patch upgraded OpenVPN to openvpn-2.4.1-2.fc25.x86_64. This patch caused the following error message to be displayed when starting up openvpn:
Options error: Unrecognized option or missing or extra parameter(s) in openvpn.conf:79: plugin (2.4.1)
Line 79 in my openvpn.conf file is:
plugin /opt/duo/duo_openvpn.so <auth data>
The duo_openvpn.so configuration worked perfectly before I upgraded openvpn. I tried rebuilding and reinstalling the duosecurity openvpn plugin using the steps in https://duo.com/docs/openvpn, but this did not resolve the problem. Is there a known solution for this problem, or is a patch needed for the duosecurity openvpn plugin?