Problemer med IIS i forbindelse med .NET

Jeg får følgende fejl:

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: Request for the permission of type 'System.Security.Permissions.FileIOPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.

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: Request for the permission of type 'System.Security.Permissions.FileIOPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.]
  System.Security.CodeAccessSecurityEngine.Check(Object demand, StackCrawlMark& stackMark, Boolean isPermSet) +0
  System.Security.CodeAccessPermission.Demand() +59
  System.Web.HttpRequest.MapPath(VirtualPath virtualPath, VirtualPath baseVirtualDir, Boolean allowCrossAppMapping) +156
  System.Web.HttpRequest.MapPath(VirtualPath virtualPath) +30
  System.Web.HttpServerUtility.Execute(String path, TextWriter writer, Boolean preserveForm) +208
  System.Web.HttpServerUtility.Transfer(String path, Boolean preserveForm) +56
  GASWeb.Business.Portal.ModuleHttpHandler.ProcessRequest(HttpContext context) in D:\Afgangsprojekt\Project\GASWebPrototype\GASWeb.Business\Portal\ModuleHttpHandler.cs:50
  System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +358
  System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +64


Nogen der ved hvilken sikkerhedsforanstalning der gør denne fejl kommer, og hvordan jeg slår det fra.