Need help... on LinqToUmbraco without a WebContext...

I have a console app that need to use LinqToUmbraco generated Entities.

CmsDataContext class that generated from the "Export to .Net" umbraco DocumentTypes .

What i did...

static void Main(string[] args)

        {

                   using (var dataProvider = new NodeDataProvider("umbraco.config", true)) 

            using (var ctx = new CmsDataContext(dataProvider))

            {

                var latestPost = (from post in ctx.BlogPostDTs

                                  orderby post.UpdateDate descending 

                                  select post).First();

            }

}

===============

RECEIVING following ERROR. Please suggest what i am doing wrong???

===============

System.TypeInitializationException was unhandled

  Message="The type initializer for 'umbraco.UmbracoSettings' threw an exception."

  Source="businesslogic"

  TypeName="umbraco.UmbracoSettings"

  StackTrace:

       at umbraco.UmbracoSettings.get_ForceSafeAliases()

       at umbraco.cms.helpers.Casing.SafeAliasWithForcingCheck(String alias)

       at umbraco.Linq.Core.Node.NodeDataProvider.LoadFromXml[T](XElement xml, T node)

       at umbraco.Linq.Core.Node.NodeTree`1.GetEnumerator()

       at System.Linq.Buffer`1..ctor(IEnumerable`1 source)

       at System.Linq.OrderedEnumerable`1.<GetEnumerator>d__0.MoveNext()

       at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)

       at EvaluateLinqToUmbracoConsoleApp.Program.Main(String[] args) in G:\Bharath\umbraco\EvaluateLinqToUmbracoConsoleApp\Program.cs:line 20

       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)

       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)

       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()

       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)

       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)

       at System.Threading.ThreadHelper.ThreadStart()

  InnerException: System.ArgumentNullException

       Message="Value cannot be null.\r\nParameter name: str"

       Source="mscorlib"

       ParamName="str"

       StackTrace:

            at System.Security.Permissions.FileIOPermission.HasIllegalCharacters(String[] str)

            at System.Security.Permissions.FileIOPermission.AddPathList(FileIOPermissionAccess access, AccessControlActions control, String[] pathListOrig, Boolean checkForDuplicates, Boolean needFullPath, Boolean copyPathList)

            at System.Security.Permissions.FileIOPermission..ctor(FileIOPermissionAccess access, String path)

            at System.Web.InternalSecurityPermissions.get_AppPathDiscovery()

            at System.Web.HttpRuntime.get_AppDomainAppPath()

            at umbraco.GlobalSettings.get_FullpathToRoot()

            at umbraco.UmbracoSettings..cctor()

       InnerException: