Untitled

<html ng-app="Crm">
<body ng-controller="CrmCtrl">
<form name="novoCrmForm">
<div class="row">
    <div class="form-group text-left col-md-8">
        <label for="Nome">Nome <i class="danger">*</i></label>
        <input type="text" class="form-control" ng-model="empresaParticipante.NOME_FANTASIA" ng-required="true" name="NOME_FANTASIA" placeholder="Nome">
    </div>
    <div class="form-group text-left col-md-4">
        <label for="cpf">CPF</label>
        <input type="text" class="form-control" ng-model="empresaParticipante.CNPJ_CPF" name="CNPJ_CPF" placeholder="CPF">
    </div>
</div>
<div class="row">
    <div class="form-group text-left col-md-6">
        <label for="Telefone">Telefone</label>
        <input type="tel" class="form-control" ng-model="empresaParticipante.TELEFONE_01" name="TELEFONE_01" placeholder="Telefone">
    </div>
    <div class="form-group text-left col-md-6">
        <label for="Celular">Celular <i class="danger">*</i></label>
        <input type="text" class="form-control" ng-model="empresaParticipante.CELULAR" ng-required="true" name="CELULAR" placeholder="Celular">
    </div>
</div>
<div class="row">
    <div class="form-group text-left col-md-12">
        <label for="Email">Email <i class="danger">*</i></label>
        <input type="email" class="form-control" ng-model="empresaParticipante.EMAIL" ng-required="true" name="EMAIL" placeholder="Email">
    </div>
</div>
</form>
</div>
</div>

<button class="btn btn-info" data-dismiss="modal" ng-click="adicionarRegistro(empresaParticipante)" ng-disabled="novoCrmForm.$invalid">Salvar</button>

var crmApp = angular.module("Crm", []);
crmApp.controller("CrmCtrl", function ($scope, $http) {


$scope.adicionarRegistro = function (empresaParticipante) {
    $http.post("http://localhost:50183/api/crm/salvar", JSON.stringify(empresaParticipante)).success(function (data) {
        delete $scope.empresaParticipante;
        $scope.novoCrmForm.$setPristine();
        console.log(empresaParticipante);
        carregarRegistros();
    });
};

carregarRegistros();
});

{"NOME_FANTASIA":"bruno","CNPJ_CPF":"111.222.333-44","TELEFONE_01":"(000) 00000-0011","CELULAR":"(000) 00000-0022","EMAIL":"teste@teste.com.br"}

{"mensagem":"Store update, insert, or delete statement affected an unexpected number of rows (0). Entities
 may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId
=472540 for information on understanding and handling optimistic concurrency exceptions.","objeto":null
,"lista":[],"status":false}

[Route("salvar")]
    [HttpPost]
    public HttpResponseMessage post([FromBody] EMPRESAS_PARTICIPANTES empresaParticipante)
    {
        IEmpresas_ParticipantesBO Empresas_ParticipantesBO = new Empresas_ParticipantesBO();
        Retorno retorno = new Retorno();

        try
        {
            //salvar
            retorno = Empresas_ParticipantesBO.salvar(empresaParticipante);