Me too. ip open logging page. ip:943/admin make this error.
Access server installed to cloud (jelastic), ubuntu 18.04.3 LTX x86. I take public static ip.
https://openvpn.net/for/site-to-site-vpn/ >
https://openvpn.net/quick-start-guide/ >
https://openvpn.net/vpn-software-packages/ and then ubuntu, 18, 64 bits. All commands go throu without problems. Then password.
After this, accessserverstaticip:943/admin, username openvpn + passwd, make this error.
In my opinion it is not clever idea concentrate Jelastic. It is similar platform as amazon etc. Of course it is possible found errors from it side, but much better is try check Ubuntu first.
https://forums.unraid.net/topic/79012-support-linuxserverio-openvpn-as/page/73/
This tell "iptables", "capadd network admin", "wrong network method". I try search more information all of this, but "where is iptables" no clear answer. "capadd"- cannot found "how"--- is this any hidden config-file, "wrong network method"- how to adjust this. After 2 hour googling I found any "install docker"... but it also does not looks clear.
https://discourse.linuxserver.io/t/just-installed-openvpn-as-cant-login-as-admin/1162
This also speak this "cap add", but still no any manual does not tell where this "cap add is...". Also this speak any "portainer", is it any config file or any software?
In my opinion, problem must be very easy to solve. Ubuntu is new and clear. Openvpn access server installed using just step-by-step using clear information. So, maybe simply I must found any clear checklist "/etc/bin/xyz/configfile, check it" etc. Information I found was good, but "cap add network" etc is not informatic... even google cannot help "how to edit"...