agent doesn't connect to server through https

I am using ubuntu 16.04 and I am trying to do inventory using snmp protocol, in the wiki, it's mentioned that I should use https otherwise ocs won't do the inventory based on snmp

 i created ssl certificate  and now i can access the server's page through https://192.168.86.135 , it's secured and the admin consol works fine too
but when i  try to connect to the server from the agent i run into this error:

[error] Cannot establish communication : 500 Can't connect to 192.168.86.135:443 (certificate verify failed)

I don't know what to do !