The type initiator of 'Oracle.DataAccess.Client.OracleConnection' raised an exception with C #

My wpf program worked very well. They moved, to make some changes. Well, I was asked to change some folders in the application. Before I make any changes I ran the application and it is giving me this error:

  

The type initializer for 'Oracle.DataAccess.Client.OracleConnection'   has thrown an exception

The fact occurs in this line:

var diferenca = _listaCommiter().Except(_listaFarm());

This is the complete method code:

private List<string> RetornaDiferenca()
{
    List<string> listaDiferenca = new List<string>();

    try
    {
        var diferenca = _listaCommiter().Except(_listaFarm());

        foreach (var _diferenca in diferenca)
        {
            listaDiferenca.Add(_diferenca);
        }

        diferenca = null;

        return listaDiferenca;
    }
    catch (Exception ex)
    {
        string r = ex.Message;
        return null;
    }
}

This is the method _listaFarm()

private List<string> _listaFarm()
{
    List<string> lista = new List<string>();

    ConexaoBanco cb = new ConexaoBanco();

    lista = cb.CriaConexao();

    return lista;
}

It's a select on a DB table.

I noticed that in the method where I get the connection, it's giving the problem. Here's the method:

public List<string> CriaConexao()
{
    string conexao = ConfigurationManager.ConnectionStrings["FarmExternaConnect"]
                .ConnectionString;
    List<string> listaArquivoFarmExterna = new List<string>();

    OracleConnection conn = new OracleConnection(conexao);
    conn.Open();

    OracleCommand cmd = new OracleCommand();
    cmd.Connection = conn;
    cmd.CommandText = "select path, arquivo from gh_arquivos_farm_externa";
    cmd.CommandType = CommandType.Text;

    try
    {
        OracleDataReader dr = cmd.ExecuteReader();

        while (dr.Read())
        {
            listaArquivoFarmExterna.Add(dr.GetString(0) + dr.GetString(1));
        }

        return listaArquivoFarmExterna;
    }
    catch(Exception ex)
    {
        return null;
    }
    finally
    {
        conn.Close();
        cmd.Dispose();
    }

The error goes along this line: OracleConnection conn = new OracleConnection(conexao);

This is the inner exception:

  

The provider is not compatible with the Oracle client version

My connection string:

<add name="FarmExternaConnect" connectionString="Data Source=DESENV; Persist Security Info=True; User ID=Eu; Password=teste"/>

More rows in my app.config

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="entityFramework"
      type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=xxxxxxxxxxxx"
      requirePermission="false"/>
    <section name="oracle.manageddataaccess.client"
      type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=xxxxxxxxxxxx"/>
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5"/>
  </startup>
  <appSettings>
    <!-- Pastas de Projetos .NET que estão na Farm Externa, separados por vírgula -->
    <add key="ProjetosDotNet" value="teste"/>
  </appSettings>

   <connectionStrings>
     <add name="FarmExternaConnect" connectionString="Data Source=DESENV; Persist Security Info=True; User ID=user; Password=teste"/>
   </connectionStrings>

  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework"/>
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer"/>
    </providers>
  </entityFramework>
  <system.data>
    <DbProviderFactories>
      <remove invariant="Oracle.ManagedDataAccess.Client"/>
      <add name="ODP.NET, Managed Driver" invariant="Oracle.ManagedDataAccess.Client" description="Oracle Data Provider for .NET, Managed Driver"
        type="Oracle.ManagedDataAccess.Client.OracleClientFactory, Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=xxxxxxxxxxxxxxx"/>
    </DbProviderFactories>
  </system.data>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <publisherPolicy apply="no"/>
        <assemblyIdentity name="Oracle.ManagedDataAccess" publicKeyToken="xxxxxxxxxxxxxxx" culture="neutral"/>
        <bindingRedirect oldVersion="4.121.0.0 - 4.65535.65535.65535" newVersion="4.121.2.0"/>
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <oracle.manageddataaccess.client>
    <version number="*">
      <dataSources>
        <dataSource alias="SampleDataSource" descriptor="(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=ORCL))) "/>
      </dataSources>
    </version>
  </oracle.manageddataaccess.client>
</configuration>