In my case with the same error code, this is by inconsistent name resolution.
Cell Manager and the client resolve by DNS with fully FQDN name. But in the client there is a bad entry.
But in /etc/hosts file there is an entry with a short name. For this reason when you try get the config we receive *RETVAL*8709 error.
For example:
DNS name is: host.domain.com
This is installed ok.
Integration execute ok, but when try to check it you receive the error.
Because de client has an entry in /etc/hosts like this:
10.10.10.10 host
this was changed to:
10.10.10.10 host.domain.com host