Error when user start workflow in a item list: ProfileDBCacheService.GetUserDataInternal Exception: System.NullReferenceException: Object reference not set to an instance of an object

Hello, i have a farm with some server attached to it, and in one of them i get the following error in log when user is trying to execute a lista workflow: 

ProfileDBCacheService.GetUserDataInternal Exception: System.NullReferenceException: Object reference not set to an instance of an object

$proxy = Get-SPServiceApplicationProxy | ?{$_.TypeName -eq 'User Profile Service Application Proxy'}
Update-SPRepopulateMicroblogFeedCache -ProfileServiceApplicationProxy $proxy -AccountName domain\userName

Update-SPRepopulateMicroblogFeedCache : UserProfileDBCache_WCFLogging ::
ProfileDBCacheServiceClient.GetUserData threw
exceptionSystem.ServiceModel.Security.SecurityAccessDeniedException
At line:1 char:1+ Update-SPRepopulateMicroblogFeedCache -ProfileServiceApplicationProxy $proxy
-Ac ...+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~+ CategoryInfo          : InvalidData: (Microsoft.Offic...roblogFeedCache:
   SPCmdletUpdateMicroblogFeedCache) [Update-SPRepopulateMicroblogFeedCache],
   UserProfileApplicationNotAvailableException+ FullyQualifiedErrorId : Microsoft.Office.Server.UserProfiles.PowerShell.
   SPCmdletUpdateMicroblogFeedCache

-I tried to develop a simple console application in visual studio 2013 using the ProfileDBCacheService.svc with the code bellow:

using ConsoleApplication1.ServiceReference1;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            ServiceReference1.ProfileDBCacheServiceClient client = new ServiceReference1.ProfileDBCacheServiceClient();
            UserSearchCriteria user = new UserSearchCriteria();
            string [] emails = new string[1];
            emails[0] = "emailofuser";
            user.EmailCollection = emails;
            string [] users = new string[1];
            users[0] = "domain\user";
            user.NTNameCollection = users;
            user.PartitionID = Guid.NewGuid();
            user.SearchColumn = "NTName";
            StreamedDataOfArrayOfUserDatajHCugpoN result = client.GetUserData(user);
            string a;

            // Use the 'client' variable to call operations on the service.

            // Always close the client.
            client.Close();
        }
    }
}

but i get the error "Additional information: An endpoint configuration section for contract 'ServiceReference1.IProfileDBCacheService' could not be loaded because more than one endpoint configuration for that contract was found"

What else can i check?