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Question

PrincipalConext is giving this error. :

PrincipalContext yourDomain = new PrincipalContext(ContextType.Domain);

public bool GetUserGroupInfo(string userName, string PrincipalSamAccountName) {

 bool UserAvailableFlg = false; try { string[] vs = userName.Split('@');

PrincipalContext yourDomain = new PrincipalContext(ContextType.Domain);
            UserPrincipal user = UserPrincipal.FindByIdentity(yourDomain, userName);
            UserDisplayName = user.DisplayName;
            if (user != null)
            {
                var grp = user.GetAuthorizationGroups().Where(n =\> n.SamAccountName.Equals(PrincipalSamAccountName)).FirstOrDefault();
                if (grp != null)
                {
                    PrincipalCollection principals = ((GroupPrincipal)grp).Members;



                    var users = (from n in principals
                                 where n.SamAccountName.Equals(vs\[0\])
                                 select new
                                 {
                                    n.Name,
                                    n.SamAccountName
                                 }).ToList();
                    if (users != null)
                    {
                        UserAvailableFlg = true;
                    }
                }
            }
        }
        catch (Exception ex)
        {
            return false;
        }
        return UserAvailableFlg;
    }