.net – System.DirectoryServices.DirectoryServicesCOMException: An operations error occurred

I have the same web app working in three others servers. Anyone have any idea why is not working in the 4th server? See the error and stacktrace:

An operations error occurred.

Description: An unhandled exception occurred during the execution of
the current web request. Please review the stack trace for more
information about the error and where it originated in the code.

Exception Details:
System.DirectoryServices.DirectoryServicesCOMException: An operations
error occurred.

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:

[DirectoryServicesCOMException (0x80072020): An operations error
occurred. ] System.DirectoryServices.DirectoryEntry.Bind(Boolean
throwIfFail) +454 System.DirectoryServices.DirectoryEntry.Bind()
+36 System.DirectoryServices.DirectoryEntry.get_AdsObject() +31 System.DirectoryServices.PropertyValueCollection.PopulateList() +22
System.DirectoryServices.PropertyValueCollection..ctor(DirectoryEntry
entry, String propertyName) +96
System.DirectoryServices.PropertyCollection.get_Item(String
propertyName) +142
System.DirectoryServices.AccountManagement.PrincipalContext.DoLDAPDirectoryInitNoContainer()
+1134 System.DirectoryServices.AccountManagement.PrincipalContext.DoDomainInit()
+37 System.DirectoryServices.AccountManagement.PrincipalContext.Initialize()
+124 System.DirectoryServices.AccountManagement.PrincipalContext.get_QueryCtx()
+31 System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithTypeHelper(PrincipalContext
context, Type principalType, Nullable'1 identityType, String
identityValue, DateTime refDate) +14
System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithType(PrincipalContext
context, Type principalType, String identityValue) +73
System.DirectoryServices.AccountManagement.UserPrincipal.FindByIdentity(PrincipalContext
context, String identityValue) +25
Infraero.TINE3.STTEnterprise.Web.Common.Seguranca.ServicoAutenticacao.EfetuarLogin(AcessoUsuario
acessoUsuario, String senha) in
D:\SVN\STT\trunk\4-0_CodigoFonte_Enterprise\4-4_SRC\Infraero.TINE3.STTEnterprise.Web\Common\Seguranca\ServicoAutenticacao.cs:34
Infraero.TINE3.STTEnterprise.Web.Controllers.LoginController.ValidarUsuarioAD(String
matricula, String senha, AcessoUsuario acessoUsuario) in
D:\SVN\STT\trunk\4-0_CodigoFonte_Enterprise\4-4_SRC\Infraero.TINE3.STTEnterprise.Web\Controllers\LoginController.cs:92
Infraero.TINE3.STTEnterprise.Web.Controllers.LoginController.ValidarUsuario(String
matricula, String senha) in
D:\SVN\STT\trunk\4-0_CodigoFonte_Enterprise\4-4_SRC\Infraero.TINE3.STTEnterprise.Web\Controllers\LoginController.cs:80
Infraero.TINE3.STTEnterprise.Web.Controllers.LoginController.Index(LoginViewModel
loginViewModel) in
D:\SVN\STT\trunk\4-0_CodigoFonte_Enterprise\4-4_SRC\Infraero.TINE3.STTEnterprise.Web\Controllers\LoginController.cs:54
lambda_method(Closure , ControllerBase , Object[] ) +108
System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase
controller, Object[] parameters) +17
System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext
controllerContext, IDictionary'2 parameters) +208
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext
controllerContext, ActionDescriptor actionDescriptor, IDictionary'2
parameters) +27
System.Web.Mvc.<>c__DisplayClass15.b__12()
+55 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter
filter, ActionExecutingContext preContext, Func'1 continuation) +263
System.Web.Mvc.<>c__DisplayClass17.b__14()
+19 System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext
controllerContext, IList'1 filters, ActionDescriptor actionDescriptor,
IDictionary`2 parameters) +191
System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext
controllerContext, String actionName) +343
System.Web.Mvc.Controller.ExecuteCore() +116
System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext)
+97 System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext
requestContext) +10
System.Web.Mvc.<>c__DisplayClassb.b__5() +37
System.Web.Mvc.Async.<>c__DisplayClass1.b__0() +21
System.Web.Mvc.Async.<>c__DisplayClass8'1.b__7(IAsyncResult
_) +12 System.Web.Mvc.Async.WrappedAsyncResult'1.End() +62 System.Web.Mvc.<>c__DisplayClasse.b__d() +50
System.Web.Mvc.SecurityUtil.b__0(Action f) +7
System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action)
+22 System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +60
System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult
result) +9
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
+8963149 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184

EfetuarLogin Method:

public static bool EfetuarLogin(User user, string password)
{
    bool isValid = false;

    if (user != null)
    {
        PrincipalContext context = new PrincipalContext(ContextType.Domain);

        using (context)
        {
            isValid = context.ValidateCredentials(user.Login, password);

            if (isValid)
            {
                UserPrincipal userAD = UserPrincipal.FindByIdentity(context, user.Login);

                MySession.CurrentUser = new MyUserSession()
                {
                    Id = user.Id,
                    ProfileId = user.ProfileId ,
                    Login = user.Login ,
                    Name = userAD.Name
                };
            }
        }
    }

    return isValid;
}