Reception of the rights to the catalogue

[talgat]

There is such code. On a call dSecurity.ModifyAccessRule appears System.Security.Principal.IdentityNotMappedException
What not so?

 public void AddDirectorySecurity(string FileName, string Account, FileSystemRights Rights, AccessControlType ControlType)
        {
            // Create a new DirectoryInfo object.
            DirectoryInfo dInfo = new DirectoryInfo(FileName);

            // Get a DirectorySecurity object that represents the 
            // current security settings.
            DirectorySecurity dSecurity = dInfo.GetAccessControl();
            FileSystemAccessRule fsAccess = new FileSystemAccessRule(
                    Account, Rights,
                    InheritanceFlags.None,
                    PropagationFlags.NoPropagateInherit,
                    ControlType);
            bool allOK;
            dSecurity.ModifyAccessRule(AccessControlModification.Add, fsAccess, out allOK);
            if (!allOK)
                throw new ApplicationException("Unable to add access rule to directory," + FileName + ", for " + Account);

            // Устанавливаем правила наследвания доступа
            FileSystemAccessRule inheritanceRule = new FileSystemAccessRule(
                    Account, Rights,
                    InheritanceFlags.ContainerInherit | InheritanceFlags.ObjectInherit,
                    PropagationFlags.InheritOnly,
                    ControlType);
            dSecurity.ModifyAccessRule(AccessControlModification.Add, inheritanceRule, out allOK);
            if (!allOK)
                throw new ApplicationException("Unable to add inheritance rule to directory," + FileName + ", for " + Account);

            // Устанавливаем новые параметры доступа.
            dInfo.SetAccessControl(dSecurity);


        }