VNC Failed to connect to server code: 1006

I have install opennebula in centos 7
And i have created one vm and it’s status is running.
and firewall also stop.

when i run https://SUNSTONE_IP:29876 then it show this

Error response

Error code 405.

Message: Method Not Allowed.

Error code explanation: 405 = Specified method is invalid for this resource…

Please help me out