Failed to make API request to SAM server

I've installed HDF 3.2 on existing HDP cluster but SAM is not starting giving the following error:

"Failed to make API request to SAM server at http://<sam_host_fqdn>:7777/api/v1/config/streamline,retrying.. 0 out of 6",

I checked network's and the host's firewall, both disabled. Has anyone had this issue, or point me to the source of the problem?

Thanks.