Search broken in SharePoint 2010 - sharepoint-2010

Question

Search in SharePoint throws an error, NullReferenceException, whether using the Search box on a normal page or even just loading the Advanced Search page.
I was originally getting System.ServiceModel.ServerTooBusyException and Round Robin Service Load Balancer EndpointFailure errors in the SharePoint ULS logs whenever I tried to search. I examined IIS and determined that the Web Apps existed. I stopped and started the Search Query and Site Settings Serviec on the server. That was the last I saw of the EndpointFailure and ServerTooBusyException errors.
However, a new error showed up. This time is was a System.NullReferenceException from SetPropertiesOnQueryReader() at CoreResultsWebPart.OnInit(). KB Article 976462 looked promising, until further research showed that it adds the AllowInsecureTransport property in the SecurityBindingElement class, and changes the value from its default of False to True. However, this property exists and is already set to True in my environment.
I found this same problem, however deleting the Search Service Apps and Proxies, recreating them and performing an IISRESET did not fix my problem.
When the Advanced Enterprise Search page is brought up, an error is returned to the screen: Object reference not set to an instance of an object.
This is the log entry out of the ULS:
CoreResultsWebPart::OnInit: Exception initializing: System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.Office.Server.Search.WebControls.CoreResultsWebPart.SetPropertiesOnQueryReader() at Microsoft.Office.Server.Search.WebControls.CoreResultsWebPart.OnInit(EventArgs e)
Internal server error exception: System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.Office.Server.Search.WebControls.CoreResultsWebPart.SetPropertiesOnQueryReader() at Microsoft.Office.Server.Search.WebControls.CoreResultsWebPart.OnInit(EventArgs e) System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.Office.Server.Search.WebControls.CoreResultsWebPart.SetPropertiesOnQueryReader() at Microsoft.Office.Server.Search.WebControls.CoreResultsWebPart.OnInit(EventArgs e)

Answer 1

Can you have a look at your search topology? Check the status of the following components:
Administration Component
Crawl Component
Query Component
It should be on-line. If it's not, click on Modify Topology and re-provision it.
Navigate to centraladmin:port/_admin/FarmServers.aspx, and check the status of your servers. It should say No action required for all servers - if it says Upgrade required, then run the product and configuration wizard on WFE and app servers depending upon your SP servers.
There may be some rogue entry in your config DB which may be causing this. As you have already re-provisioned search there may be some orphan DB causing the issue. Navigate to centraladmin:port/_admin/databaseStatus.aspx. If you don't see old orphan search DBs here, please delete the search service application, access the above URL again and check if its there. If it is then run the following PowerShell command to remove orphan DBs:
$orphanedDB = Get-SPDatabase | where{$_.Name -eq "MySearchDatabase"}
$orphanedDB.Delete()

Answer 2

I had a similar problem and following Vinod's answer noticed that the "Search Alert Status" in Search Administration was disabled (I intended it to be). Enabling it fixed the issue, meaning that the search pages now render. I was then able to disable the "Search Alert Status" again and the pages continue to work fine.
Hope this helps someone else before they reset / restart services as suggested elsewhere on the web.

Answer 3

I got the same error, restarting SharePoint server fixed my problem.

Answer 4

I just encountered the same problem, and fixed it by:
I verified that the SharePoint Web Services site existed in IIS, and that SecurityTokenServiceApplication existed as a virtual directory.
In my case, I found that the application pool that powered it was stopped due to bad creds. I fixed the creds, bounced the pool, and bounced the site.
That still didn't resolve the issue, so I moved into Sharepoint Central Admin, went to Application Management -> Manage Service Applications.
I clicked on Search Service Application and created a new crawl for my local sites, and did a full index.
Finally I clicked through all of the pieces in the search application topology, changed nothing, but applied topology changes when I was done.
That combination of things fixed it for me.