If the Local Farm (account) is not on the permissions of Search Service Application and users try to perform a search on any SharePoint site they will get an error and a correlation ID - something like below: In ULS logs you'll notice the below error: " SearchServiceApplicationProxy::GetUserPreferenceSerializeHelperForTenant–Error occured: System.ServiceModel.Security.SecurityAccessDeniedException: Access is denied. " There is a fix on this blog but it doesn't fix the issue (at least not in my case). So the solution is to run the following powershell commands: $farmID = Get-SPFarm | select id $farmID Copy the GUID returned from $farmID and go to Search Service Application click on Permissions and paste the GUID and grant Full Permissions. And that will fix the issue.