FSSO Not working

There are 5 sites IPsec between all of them.

There is a DC at the head office with a collector agent.

I am trying to get FSSO to work between all sites. The fortigate at headoffice has FSSO working correctly however the remote fortigates wont.

I can ping the Head office DC from remote sites but its as if the fortigates cant communicate with the head office DC on port 8000 looking at th debugs :

[fsae_server_init_spec:116]: num 1, idx 0, 127.0.0.1:8000 disconnect_server_only[KCM FSSO]: disconnecting _event_error[Local FSSO Agent]: error occurred in read: Connection refused

All policies do not have specific ports configure(all ports allowed)

The Windows firewall on the DC is turned off.

Please help