I have a random error trying to rebuild an examine Index. The code referenced below cycles through 4 indexes. If you click a button it will rebuild that index. It works for 3 of the 4 indexes, but fails on the forth. To make it more complicated, it only happens on our staging server and not my local computer.

Site: Umbraco 4.6.1 using ASP.NET 4

Staging Server: Windows Server 2003: IIS 6

Locally: Windows 7: IIS 7.5

Locally, I can rebuild all 4 of the indexes referenced by thte clickedButton. On staging....only 3 of the 4. They both use the same SQL Server 2005 database.

On staging, I performed the following once I received the error:

- deleted the 4 folders in APP_Date.

- Deleted umbraco.config. 

- Recycled App_pool

- Logged back in

- Rebuilt the site.

- Reran the indexes. and still only 3 of the 4 worked.

Any ideas would be greatly appreciated.

-C

The error is:

Value cannot be null.
Parameter name: String
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 
Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: String
Source Error: 

Line 28:             Button clickedButton = (Button)sender;
Line 29:             string indexToRebuild = clickedButton.CommandArgument;
Line 30:             ExamineManager.Instance.IndexProviderCollection[indexToRebuild].RebuildIndex();
Line 31:             result.Text = string.Format("Index {0} added to index queue", indexToRebuild);
Line 32:             result.Visible = true;
Source File: d:\INETPUB\sites\devsites\JewishCommunityFed\JCF1003\stagingUmbraco\usercontrols\Umbraco\ExamineIndexAdmin.ascx.cs    Line: 30 
Stack Trace: 

[ArgumentNullException: Value cannot be null.
Parameter name: String]
   System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal) +9594206
   System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info) +119
   Examine.LuceneEngine.ExamineXmlExtensions.IsExamineElement(XElement x) +132
   Examine.LuceneEngine.ExamineXmlExtensions.ExamineNodeTypeAlias(XElement x) +13
   Examine.LuceneEngine.Providers.LuceneIndexer.ValidateDocument(XElement node) +53
   UmbracoExamine.BaseUmbracoIndexer.ValidateDocument(XElement node) +265
   Examine.LuceneEngine.Providers.LuceneIndexer.AddNodesToIndex(IEnumerable`1 nodes, String type) +120
   UmbracoExamine.BaseUmbracoIndexer.AddNodesToIndex(String xPath, String type) +93
   UmbracoExamine.BaseUmbracoIndexer.PerformIndexAll(String type) +769
   Examine.LuceneEngine.Providers.LuceneIndexer.IndexAll(String type) +72
   UmbracoExamine.BaseUmbracoIndexer.PerformIndexRebuild() +86
   Examine.LuceneEngine.Providers.LuceneIndexer.RebuildIndex() +348
   usercontrols.Umbraco.ExamineIndexAdmin.RebuildClick(Object sender, EventArgs e) in d:\INETPUB\sites\devsites\JewishCommunityFed\JCF1003\stagingUmbraco\usercontrols\Umbraco\ExamineIndexAdmin.ascx.cs:30
   System.Web.UI.WebControls.Button.OnClick(EventArgs e) +118
   System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +112
   System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +176
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5563