Search return error intermittently.
In my case, it’s about 50% chance to get this error message every time when i perform a search in FAST Search center.
My environment setup is one Web Front End ( which doesn’t run the osearch14 search service ) , one App, one FAST search server and one SQL database.
After verifying the steps from microsoft. All steps are checked and error still persist.
If you are having the same problem, check if your WFE is running “Site Query and Setting Services” under Central Administration > Application Management > Manage services on servers : change the server to your Web Front End.
Turn it off and the error is now gone! Hurray!