Recently, we received a few servers with the lifecycle firmware 188.8.131.52. We use vmcli (on OMSA 8.5) to mount an iso for an unattended build. For these servers on this firmware, we get "Error: SSL Connection error" when trying to mount the iso. The TLS version was also set to 1.0 per http://en.community.dell.com/support-forums/servers/f/177/t/19996408. Any ideas?
Which version of ESXi are you using? Try setting it from racadm instead of iDRAC GUI racadm set idrac.webserver.TLSProtocol 0