SSLstream and SSLsocket

hi im getting this error when client is connecting to server

A call to SSPI failed, see inner exception. System.ComponentModel.Win32Exception (0x80004005): An unknown error occurred while processing the certificate

server code c#

            netStream = client.GetStream();
            ssl = new SslStream(netStream, false);
            ssl.AuthenticateAsServer(prog.cert, false, SslProtocols.Tls12, true);

client code android

        KeyStore trusted = KeyStore.getInstance("PKCS12");
        InputStream in = STRINGS.context.getResources().openRawResource(R.raw.server); 
        trusted.load(in, "passw".toCharArray());                                 
        in.close();                                                              
        KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
        kmf.init(trusted, "passw".toCharArray());
        SSLContext sslContext = SSLContext.getInstance("TLSv1.2");               
        sslContext.init(kmf.getKeyManagers(),null, null);
        SSLSocketFactory factory = sslContext.getSocketFactory();
        socket = (SSLSocket)  sslContext.getSocketFactory().createSocket(SERVER_IP,SERVER_PORT);
        socket.setUseClientMode(true);
        socket.startHandshake();

If somebody knows how to solve this problem please help