I need help figuring out why search doesn't return any results.  There are lots of recently updated files in the App_Data/Search folder.  When I enter a few letters that should be found, a dropdown appears under the search box that says No Results Found.  Each search attempt creates an exception in the event log akin to this one:

AssemblyVersion:7.2.0
PortalID:0
PortalName:KGBHC
UserID:1
UserName:host
ActiveTabID:87
ActiveTabName:Search Results
RawURL:/DesktopModules/internalservices/API/searchService/search?search=Minister&pageIndex=1&pageSize=15&sortOption=0&culture=en-US
AbsoluteURL:/DesktopModules/internalservices/API/searchService/search
AbsoluteURLReferrer:http://myurl/Default.aspx?tabId=87
UserAgent:Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/31.0.1650.63 Safari/537.36
DefaultDataProvider:DotNetNuke.Data.SqlDataProvider, DotNetNuke
ExceptionGUID:acb4f102-f692-4304-b4d1-8253e54056ab
InnerException:Object reference not set to an instance of an object.
FileName:
FileLineNumber:0
FileColumnNumber:0
Method:DotNetNuke.Entities.Urls.AdvancedFriendlyUrlProvider.FriendlyUrlInternal
StackTrace:
Message:
System.NullReferenceException: Object reference not set to an instance of an object.
at DotNetNuke.Entities.Urls.AdvancedFriendlyUrlProvider.FriendlyUrlInternal(TabInfo tab, String path, String pageName, String portalAlias, PortalSettings portalSettings)
at DotNetNuke.Entities.Urls.AdvancedFriendlyUrlProvider.FriendlyUrl(TabInfo tab, String path, String pageName, PortalSettings portalSettings)
at DotNetNuke.Services.Url.FriendlyUrl.DNNFriendlyUrlProvider.FriendlyUrl(TabInfo tab, String path, String pageName, PortalSettings settings)
at DotNetNuke.Common.Globals.NavigateURL(Int32 tabID, Boolean isSuperTab, PortalSettings settings, String controlKey, String language, String pageName, String[] additionalParameters)
at DotNetNuke.Services.Search.Controllers.ModuleResultController.GetDocUrl(SearchResult searchResult)
at DotNetNuke.Services.Search.Controllers.SearchControllerImpl.GetSecurityTrimmedResults(SearchQuery searchQuery, LuceneQuery luceneQuery)
at DotNetNuke.Services.Search.Controllers.SearchControllerImpl.GetResults(SearchQuery searchQuery)
at DotNetNuke.Services.Search.Controllers.SearchControllerImpl.SiteSearch(SearchQuery searchQuery)
at DotNetNuke.Web.InternalServices.SearchServiceController.GetGroupedDetailViews(SearchQuery searchQuery, Int32& totalHits, Boolean& more)
at DotNetNuke.Web.InternalServices.SearchServiceController.Search(String search, String culture, Int32 pageIndex, Int32 pageSize, Int32 sortOption)
Source:
Server Name: PSS22

It does return a username. I accidentally typo'd bk in the search box and it returned a user whose username begins with bk. It doesn't work for all usernames, though . . . confusing!

Any ideas?

I'm sorry, mohamed adam, I don't know what you're asking for.  What code?