Internal server error exception: System.NullReferenceException: Object reference not set to an instance of an object

Error Description

Recently I came across this error with SharePoint Search. I was searching in a SharePoint list and got the below error.

Error

Internal server error exception:

Troubleshoot issues with Microsoft SharePoint Foundation.

On checking the ULS logs I found the below entries

01/28/2015 10:59:51.10         w3wp.exe (0x31D8)                0x2030    SharePoint Server Search      Query      fm9a        Unexpected                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)               7001a8bf-b506-4096-b46b-003fbb5ec91b

01/28/2015 10:59:51.10         w3wp.exe (0x31D8)                0x2030    SharePoint Server Search      Query      g1j9         Exception                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)               7001a8bf-b506-4096-b46b-003fbb5ec91b

01/28/2015 10:59:51.10         w3wp.exe (0x31D8)                0x2030    SharePoint Server  Unified Logging Service       c91s        Monitorable                Watson bucket parameters: SharePoint Server 2010, ULSException14, 06175311 "sharepoint server search", 0e001b67 "14.0.7015.0", 17853a8f "microsoft.office.server.search", 0e001bd1 "14.0.7121.0", 531f1826 "tue mar 11 10:05:26 2014", 000032a4 "000032a4", 0000002d "0000002d", 4a6d3421 "nullreferenceexception", 67316a39 "g1j9"    7001a8bf-b506-4096-b46b-003fbb5ec91b

Solution 1

If you go into Central Administration -> System Settings -> Manage Services on Server. Make sure the below services are started.

- SharePoint Server Search

- Search Query and Site Settings Service

Solution 2

Click through all the Search Administration pages in Central Admin.Click through all the Search Administration pages in Central Admin. Now perform the search again. The issue should have disappeared.

Solution 3

Identify the underlying application pool for search (Reference)

Perform an application pool recycle