Parser Error Message: Access is denied

[Guest]

Hello,

I am getting the following error on a system that was previously working:
-----------
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:
'XtenderSolutions.Authentication.DirATNAuthorityProvider'.

Source Error:


Line 256: <add assembly="System.EnterpriseServices,
Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
Line 257: <add assembly="System.Web.Mobile,
Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
Line 258: <add assembly="*"/>
Line 259: </assemblies>
Line 260:


Source File:
c:\windows\microsoft.net\framework\v1.1.4322\Config\machine.config Line:
258