Hi,
we setup OPNsense (latest version of today) with OpenVPN, which works fine so far.
OpenVPN -> Servers -> Server Certificate, we use the internal OPNsense for "Server Certificate".
Error on the windows client:
Jun 09 14:46:41: OpenSSL: error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed
Client: openvpn-install-2.4.6-I602.exe, latest version from openvpn.net. Same issue with Viscosity as openvpn-client.
Solution: On client export use "Inline Configuration", "other" and NOT Archive.
Hopefully also for someone else.
Best