OPENVPN BUG

[macafee]

OPNsense 15.7.6-amd64
FreeBSD 10.1-RELEASE-p16
OpenSSL 1.0.2d 9 Jul 2015

I'm using openvpn p2p sharekey mode but the openvpn server can't startup when I select the option of Duplicate Connections.

Duplicate Connections "Allow multiple concurrent connections from clients using the same Common Name.
NOTE: This is not generally recommended, but may be needed for some scenarios. "

The openvpn log:
Aug 7 17:38:39    openvpn[39539]: Use --help for more information.
Aug 7 17:38:39    openvpn[39539]: Options error: --duplicate-cn requires --mode server