I received blank result while pressing the search button on my site.

When I use host->search admin and click on the Re-Index Content link button I get the following error:

Error: Search Admin is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: The type initializer for 'DotNetNuke.Services.Search.IndexingProvider' threw an exception. ---> System.TypeInitializationException: The type initializer for 'DotNetNuke.Services.Search.IndexingProvider' threw an exception. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Framework.Reflection.CreateObject(String ObjectProviderType, String ObjectProviderName, String ObjectNamespace, String ObjectAssemblyName, Boolean UseCache) at DotNetNuke.Framework.Reflection.CreateObject(String ObjectProviderType, Boolean UseCache) at DotNetNuke.Services.Search.IndexingProvider.CreateProvider() at DotNetNuke.Services.Search.IndexingProvider..cctor() --- End of inner exception stack trace --- at DotNetNuke.Services.Search.IndexingProvider.Instance() at DotNetNuke.Services.Search.SearchEngine.IndexContent() at DotNetNuke.Modules.Admin.Search.SearchAdmin.cmdReIndex_Click(Object sender, EventArgs e) --- End of inner exception stack trace ---

Checking into event viewer, I noticed the following error, please help.

ModuleId: 337
ModuleDefId: 85
FriendlyName: Search Admin
ModuleControlSource: Admin/Search/SearchAdmin.ascx
AssemblyVersion: 04.09.00
PortalID: 2
PortalName: Schuurman Beloningsadvies
UserID: 1
UserName: host
ActiveTabID: 29
ActiveTabName: Search Admin
RawURL: /Host/Search Admin/tabid/29/portalid/2/Default.aspx
AbsoluteURL: /Default.aspx
AbsoluteURLReferrer: http://www.schuurman.net/Host/Search%20Admin/tabid/29/portalid/2/Default.aspx
UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.04506; .NET CLR 3.5.21022)
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: 0f582abb-4943-406e-951a-9a3123b3a605
InnerException: The type initializer for 'DotNetNuke.Services.Search.IndexingProvider' threw an exception.
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: DotNetNuke.Framework.Reflection.CreateObject
StackTrace:
Message: DotNetNuke.Services.Exceptions.ModuleLoadException: The type initializer for 'DotNetNuke.Services.Search.IndexingProvider' threw an exception. ---> System.TypeInitializationException: The type initializer for 'DotNetNuke.Services.Search.IndexingProvider' threw an exception. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Framework.Reflection.CreateObject(String ObjectProviderType, String ObjectProviderName, String ObjectNamespace, String ObjectAssemblyName, Boolean UseCache) at DotNetNuke.Framework.Reflection.CreateObject(String ObjectProviderType, Boolean UseCache) at DotNetNuke.Services.Search.IndexingProvider.CreateProvider() at DotNetNuke.Services.Search.IndexingProvider..cctor() --- End of inner exception stack trace --- at DotNetNuke.Services.Search.IndexingProvider.Instance() at DotNetNuke.Services.Search.SearchEngine.IndexContent() at DotNetNuke.Modules.Admin.Search.SearchAdmin.cmdReIndex_Click(Object sender, EventArgs e) --- End of inner exception stack trace ---
Source:
Server Name: MUIDERPOORT

Thanks for the post Sebastian - it helped. I had the same problem, probably caused by multiple upgrades and the web config section searchDataStore defaultProvider="SearchDataStoreProvider" was missing.