Check your postgresql data provider application and the ConfD developer log. Your data provider application seems to have failed to provide the data requested by the query.
I hope there no issue in postgresql data provider, since other models are fine getting the data.
Ans I had verified ConfD developer log (devel.log and confd.log), not observed any errors.
Guide me where i can debug the error, need to enable any other logs to get more details .
Then the issue is likely related to that the session in your jsonrpc.cookie is down. Check your audit.log for example.
So, for example, check if your session timed out. From the confd.conf(5) man page
/confdConfig/webui/idleTimeout (xs:duration) [PT30M]
Maximum idle time before terminating a Web UI session. PT0M means no timeout. Default is PT30M, ie 30 minutes.
/confdConfig/webui/absoluteTimeout (xs:duration) [PT60M]
Maximum absolute time before terminating a Web UI session. PT0M means no timeout. Default is PT60M, ie 60 minutes.