System.Configuration.ConfigurationErrorsException произошла после попытки извлечь данные, работающие с Entity Framework с базой данных Oracle

Question

Я получаю ошибку System.Configuration.ConfigurationErrorsException при попытке получить данные из базы данных.

app.config dal (который подключается к базе данных) выглядит следующим образом:

<?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=b77a5c561934e089"
                 requirePermission="false"/>
        <section name="oracle.manageddataaccess.client"
                 type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
    </configSections>
    <connectionStrings>
        <add name="Entities3" 
             connectionString="metadata=res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl;provider=Oracle.ManagedDataAccess.Client;provider connection string=&quot;DATA SOURCE=localhost:1521/ora;PASSWORD=*******;PERSIST SECURITY INFO=True;USER ID=*****&quot;"
             providerName="System.Data.EntityClient"/>
        <add name="OracleDbContext" providerName="Oracle.ManagedDataAccess.Client"
             connectionString="User Id=oracle_user;Password=oracle_user_password;Data Source=oracle"/>
    </connectionStrings>
    <entityFramework>
        <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
            <parameters>
                <parameter value="v13.0"/>
            </parameters>
        </defaultConnectionFactory>
        <providers>
            <provider invariantName="System.Data.SqlClient" 
                      type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer"/>
            <provider invariantName="Oracle.ManagedDataAccess.Client"
                       type="Oracle.ManagedDataAccess.EntityFramework.EFOracleProviderServices, Oracle.ManagedDataAccess.EntityFramework, Version=6.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
        </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=89b483f429c47342"/>
        </DbProviderFactories>
    </system.data>
    <runtime>
        <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <publisherPolicy apply="no"/>
        <assemblyIdentity name="Oracle.ManagedDataAccess" publicKeyToken="89b483f429c47342" 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>

app.config моих winforms, где я пытался получить данные, выглядит так:

<configuration>
  <configSections>

    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <section name="entityFramework"
      type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
      requirePermission="false"/>
    <section name="oracle.manageddataaccess.client"
      type="OracleInternal.Common.ODPMSectionHandler, Oracle.ManagedDataAccess, Version=4.121.2.0, Culture=neutral, PublicKeyToken=89b483f429c47342"/>
  </configSections>
 <connectionStrings>
    <add name="Entities3" connectionString="metadata=res://*/Model1.csdl|res://*/Model1.ssdl|res://*/Model1.msl;provider=Oracle.ManagedDataAccess.Client;provider connection string=&quot;DATA SOURCE=localhost:1521/ora;PASSWORD=******;PERSIST SECURITY INFO=True;USER ID=****&quot;" providerName="System.Data.EntityClient" />
    <add name="OracleDbContext" providerName="Oracle.ManagedDataAccess.Client" connectionString="User Id=oracle_user;Password=oracle_user_password;Data Source=oracle" />

  </connectionStrings>
<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=89b483f429c47342"/>
    </DbProviderFactories>
  </system.data>
</configuration>

Я использую этих двух провайдеров

Oracle.ManagedDataAccess.EntityFramework

и

Oracle.ManagedDataAccess

Почему это происходит?