Привет помогите разобраться с такой проблемой, при входе на сайт вылезает вот это

Server Error in '/' Application.
Security Exception
Description: The application attempted to perform an operation not allowed by the security policy. To grant this application the required permission please contact your system administrator or change the application's trust level in the configuration file.

Exception Details: System.Security.SecurityException: That assembly does not allow partially trusted callers.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[SecurityException: That assembly does not allow partially trusted callers.]
Microsoft.Practices.EnterpriseLibrary.Common.Configuration.ObjectBuilder.EnterpriseLibraryFactory..cctor() in EnterpriseLibraryFactory.cs:58

Version Information: Microsoft .NET Framework Version:2.0.50727.1434; ASP.NET Version:2.0.50727.1434