Error SQL data reader - asp.net

Question

I created Intranet project which connect with AD to retrieve User's
data as Image , Department . I did my code and it works well but I had
the below error a lot of times .
string User = ConfigurationManager.AppSettings["User"];
string Password = ConfigurationManager.AppSettings["Password"];
var entry = new DirectoryEntry("LDAP://" + "xxxxx", User, Password);
DirectorySearcher searcher = new DirectorySearcher(entry);
searcher.SearchScope = SearchScope.Subtree;
string UserName = Page.User.Identity.Name;
searcher.Filter = string.Format(CultureInfo.InvariantCulture, "(sAMAccountName={0})", UserName.Split('\\')[1]);
SearchResult findUser = searcher.FindOne();
if (findUser != null)
{
DirectoryEntry user = findUser.GetDirectoryEntry();
//string loginuser = user.Properties["UserName"].Value.ToString();
LoggedUser = user.Properties["displayName"].Value.ToString();
Session.Add("LoggedUser", LoggedUser);
LoggedEmail = user.Properties["mail"].Value.ToString();
Session.Add("LoggedEmail", LoggedEmail);
string Mobile = user.Properties["Mobile"] != null && user.Properties["Mobile"].Value != null ? user.Properties["Mobile"].Value.ToString() : null;
string Login = user.Properties["sAMAccountName"].Value.ToString();
if (user.Properties["Department"].Value != null)
LoggedDepartement = user.Properties["Department"].Value.ToString();
_userDept = user.Properties["Department"].Value != null ? user.Properties["Department"].Value.ToString() : "";
ftier.AddLoggedUser(LoggedUser, LoggedDepartement, title, LoggedEmail, data, DateTime.Now, DateTime.Now, " nnnnn", true);

Answer 1

When I've done this in the past one of the problems was unusual characters in the properties of the user object caused this sort of error.
One approach would be to put error checking on each of the variables you're setting so the code can keep working, or export to a text file all the data and go through it using excel and look for unusual or strange control characters.
If the error always occurs at a certain person you could just look at the properties of that user and hope to find the issue that way.
Our issue was the use of Chinese simplified characters in some fields.
Hope this helps you track down your issue.
Dorje