MS Indexing Service: The Silent Killer

One of the strangest .NET bugs to hit me.

Ever seen this message:

Configuration Error
Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: Access is denied: ‘Microsoft.ApplicationBlocks.Data’.

Source Error:

Line 196: <add assembly=”System.EnterpriseServices, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a”/>
Line 197: <add assembly=”System.Web.Mobile, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a”/>
Line 198: <add assembly=”*”/>
Line 199: </assemblies>
Line 200: </compilation>

Well, it actually has nothing to do with the MS app block assembly. It is actually a problem with MS Indexing Service & ASP.NET. Apparently, MS Indexing Service likes to lock files that ASP.NET might be using.

The solution is to STOP the Indexing Service, or exclude the temp ASP.NET directory from its’ scan.

MS KB article here.