The error message is clear enough. Some cert data isn't valid. But the debugging data provided seems a bit meager to me. How do I find cert 128? What is confusing is this file is up to date, so this bug cannot be unique to me, yet I don't find these error message in searches.
uname -a FreeBSD peets 11.0-RELEASE-p9 FreeBSD 11.0-RELEASE-p9 #0: Tue Apr 11 08:48:40 UTC 2017 root@amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC amd64
Jul 1 00:25:37 peets openvpn[57897]: OpenVPN 2.4.3 amd64-portbld-freebsd11.0 [SSL (OpenSSL)] [LZO] [LZ4] [MH/RECVDA] [AEAD] built on Jun 24 2017
Jul 1 00:25:37 peets openvpn[57897]: library versions: OpenSSL 1.0.2k-freebsd 26 Jan 2017, LZO 2.10
Jul 1 00:25:37 peets openvpn[57898]: Diffie-Hellman initialized with 4096 bit key
Jul 1 00:25:37 peets openvpn[57898]: Cannot load CA certificate file /usr/local/share/certs/ca-root-nss.crt (entry 128 did not validate)
Jul 1 00:25:37 peets openvpn[57898]: Cannot load CA certificate file /usr/local/share/certs/ca-root-nss.crt (only 169 of 170 entries were valid X509 names)
Jul 1 00:25:37 peets openvpn[57898]: Exiting due to fatal error