Yes, the filename must be cacert.pem.
My agent is latest microsoft winodows agent.
I use packager to make auto installer.
/S /NOW /NO_SYSTRAY /SSL=1 /SERVER=https://<my domain IP>/ocsinventory
I already try use cert.pem, chain.pem and fullchain.pem and rename to cacert.pem.
All of them are same error result.
cert.pem have one certiticate
chain.pem have one certiticate
fullchain.pem = cert.pem + chain.pem