TlsFailureException when trying to instanciate a CollaborationPlataform with ServerPlataformSettings

Hello, i'm trying to connect my application endpoint to a OCS Front End. I have done the provisioning process, and i created a certificate that is in Certificates (Local Computer)\Personal\Certificates. But when i try to initialize the collaboration plataform:

            ServerPlatformSettings settings = new ServerPlatformSettings(_applicationName, _localhost, _servicePort, _serverGruu, cert);

            _collabPlatform = new CollaborationPlatform(settings);

i have the following exception:  TlsFailureException (i have runned the console application with Administrator) 

Microsoft.Rtc.Signaling.TlsFailureException was unhandled

  Message="The operation failed due to issues with Tls. See the exception for more information."

  Source="Microsoft.Rtc.Collaboration"

  DetectionStackTrace="   at System.Environment.get_StackTrace()\r\n   at Microsoft.Rtc.Signaling.RealTimeException..ctor(String message, Exception innerException)\r\n   at Microsoft.Rtc.Signaling.TlsFailureException..ctor(String message, Exception innerException, Int32 errorCode, TlsFailureReason tlsFailureReason)\r\n   at Microsoft.Rtc.Signaling.RealTimeServerTlsConnectionManager.SetDefaultTlsTuple()\r\n   at Microsoft.Rtc.Signaling.RealTimeConnectionManager.SetLocalCertificate(String certificateIssuerName, Byte[] certificateSerialNumber)\r\n   at Microsoft.Rtc.Signaling.RealTimeServerTlsConnectionManager.SetLocalCertificate(String certificateIssuerName, Byte[] certificateSerialNumber)\r\n   at Microsoft.Rtc.Signaling.RealTimeConnectionManager..ctor(String localHost, String certificateIssuerName, Byte[] certificateSerialNumber)\r\n   at Microsoft.Rtc.Signaling.RealTimeServerConnectionManager..ctor(String localHost, String certificateIssuerName, Byte[] certificateSerialNumber)\r\n   at Microsoft.Rtc.Signaling.RealTimeServerTlsConnectionManager..ctor(String localHost, String certificateIssuerName, Byte[] certificateSerialNumber)\r\n   at Microsoft.Rtc.Collaboration.CollaborationPlatform.CreateConnectionManager()\r\n   at Microsoft.Rtc.Collaboration.CollaborationPlatform.Initialize(CollaborationPlatformSettings platformSettings)\r\n   at Microsoft.Rtc.Collaboration.CollaborationPlatform..ctor(ServerPlatformSettings platformSettings)\r\n   at UCMASampleCode_PublishAlwaysOnline.PublishAlwaysOnline.InitalizePlatform() in C:\\Users\\Telmo\\Desktop\\PublishAlwaysOnline\\PublishAlwaysOnline.cs:line 66\r\n   at UCMASampleCode_PublishAlwaysOnline.PublishAlwaysOnline.Run() in C:\\Users\\Telmo\\Desktop\\PublishAlwaysOnline\\PublishAlwaysOnline.cs:line 51\r\n   at UCMASampleCode_PublishAlwaysOnline.PublishAlwaysOnline.Main(String[] args) in C:\\Users\\Telmo\\Desktop\\PublishAlwaysOnline\\PublishAlwaysOnline.cs:line 44"

  ErrorCode=-2146893042

  StackTrace:

       at Microsoft.Rtc.Signaling.RealTimeServerTlsConnectionManager.SetDefaultTlsTuple()

       at Microsoft.Rtc.Signaling.RealTimeConnectionManager.SetLocalCertificate(String certificateIssuerName, Byte[] certificateSerialNumber)

       at Microsoft.Rtc.Signaling.RealTimeServerTlsConnectionManager.SetLocalCertificate(String certificateIssuerName, Byte[] certificateSerialNumber)

       at Microsoft.Rtc.Signaling.RealTimeConnectionManager..ctor(String localHost, String certificateIssuerName, Byte[] certificateSerialNumber)

       at Microsoft.Rtc.Signaling.RealTimeServerConnectionManager..ctor(String localHost, String certificateIssuerName, Byte[] certificateSerialNumber)

       at Microsoft.Rtc.Signaling.RealTimeServerTlsConnectionManager..ctor(String localHost, String certificateIssuerName, Byte[] certificateSerialNumber)

       at Microsoft.Rtc.Collaboration.CollaborationPlatform.CreateConnectionManager()

       at Microsoft.Rtc.Collaboration.CollaborationPlatform.Initialize(CollaborationPlatformSettings platformSettings)

       at Microsoft.Rtc.Collaboration.CollaborationPlatform..ctor(ServerPlatformSettings platformSettings)

       at UCMASampleCode_PublishAlwaysOnline.PublishAlwaysOnline.InitalizePlatform() in C:\Users\Telmo\Desktop\PublishAlwaysOnline\PublishAlwaysOnline.cs:line 66

       at UCMASampleCode_PublishAlwaysOnline.PublishAlwaysOnline.Run() in C:\Users\Telmo\Desktop\PublishAlwaysOnline\PublishAlwaysOnline.cs:line 51

       at UCMASampleCode_PublishAlwaysOnline.PublishAlwaysOnline.Main(String[] args) in C:\Users\Telmo\Desktop\PublishAlwaysOnline\PublishAlwaysOnline.cs:line 44

  InnerException: Microsoft.Rtc.Internal.Sip.TLSException

       Message="CertificateInfoNative::AcquireCredentialsHandle() failed; HRESULT=-2146893042"

       Source="SIPEPS"

       ErrorCode=-2146893042

       StackTrace:

            at Microsoft.Rtc.Internal.Sip.CertificateInfoNative.AcquireCredentialsHandleW(CertificateInfoNative* )

            at Microsoft.Rtc.Internal.Sip.CertificateInfoNative.{ctor}(CertificateInfoNative* , SipConnectionDirection isIncoming, String issuerName, Byte[] serialNumber, Int32 serialNumberLength, Boolean reverseIssuerName)

            at Microsoft.Rtc.Internal.Sip.TlsCredentials..ctor(SipConnectionDirection isIncoming, String issuerName, Byte[] serialNumber, String[] allowedDomains, String[] allowedEnhancedKeyUsage)

            at Microsoft.Rtc.Signaling.RealTimeServerTlsConnectionManager.SetDefaultTlsTuple()

       InnerException: