The type initializer for 'System.Data.Entity.I

问题:

I'm working with EF5 in a MVC 4 aspnet website. Locally, everything works just fine, but when I publish it to the IIS and try to enter, I get the error

"The type initializer for 'System.Data.Entity.Internal.AppConfig' threw an exception."

Detailed exception

An error occurred creating the configuration section handler for entityFramework: Configuration for DbContext type 'GdpSoftware.Server.Data.GdpSoftwareDbContext, GdpSoftware.Server.Data' is specified multiple times in the application configuration. Each context can only be configured once. (E:\App\web.config line 104)

I checked previous question in StackOverflow, and I already uninstalled and reinstalled through Nuget EntityFramework and checked that each reference to it in each project is EF5. I also checked that the selected framework in each project is 4.5.

Any idea, What might be causing the issue? Thanks! Guillermo.

web.config

<?xml version="1.0" encoding="utf-8"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->
<configuration>
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />

  <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --></configSections>
  <connectionStrings>
    <add name="GdpSoftwareConnectionString" connectionString="Persist Security Info=False;User ID=user;Password=password;Initial Catalog=databasename;Data Source=server" providerName="System.Data.SqlClient" />
    <add name="GdpSoftware.Server.Data.GdpSoftwareDbContext" connectionString="GdpSoftware.Server.Data.GdpSoftwareDbContext_ConnectionString" providerName="System.Data.SqlClient"/>
    <add name="GdpSoftware.Server.Ui.Web.Models.UsersContext" connectionString="GdpSoftware.Server.Ui.Web.Models.UsersContext_ConnectionString" providerName="System.Data.SqlClient"/>
  </connectionStrings>
  <appSettings>
    <add key="webpages:Version" value="2.0.0.0" />
    <add key="webpages:Enabled" value="false" />
    <add key="PreserveLoginUrl" value="true" />
    <add key="ClientValidationEnabled" value="true" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
  </appSettings>
  <system.web>
    <compilation debug="true" targetFramework="4.5" />
    <httpRuntime targetFramework="4.5" />
    <authentication mode="Forms">
      <forms loginUrl="~/Account/Login" timeout="2880" />
    </authentication>
    <pages>
      <namespaces>
        <add namespace="System.Web.Helpers" />
        <add namespace="System.Web.Mvc" />
        <add namespace="System.Web.Mvc.Ajax" />
        <add namespace="System.Web.Mvc.Html" />
        <add namespace="System.Web.Optimization" />
        <add namespace="System.Web.Routing" />
        <add namespace="System.Web.WebPages" />
      </namespaces>
    </pages>
    <!-- BEGIN - TO SEE THE ERRORS ON THE DEPLOYMENT-->
    <customErrors mode="Off" />
    <!-- END - TO SEE THE ERRORS ON THE DEPLOYMENT-->
  </system.web>
  <system.webServer>
    <!-- BEGIN - TO SEE THE ERRORS ON THE DEPLOYMENT-->
    <httpErrors errorMode="Detailed" />
    <asp scriptErrorSentToBrowser="true" />
    <!-- END - TO SEE THE ERRORS ON THE DEPLOYMENT-->
    <validation validateIntegratedModeConfiguration="false" />
    <handlers>
      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" />
      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" />
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0" />
      <add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
    <staticContent>
      <mimeMap fileExtension=".mustache" mimeType="text/plain" />
    </staticContent>
    <security>
      <requestFiltering>
        <fileExtensions>
          <add fileExtension=".mustache" allowed="true" />
        </fileExtensions>
      </requestFiltering>
    </security>
  </system.webServer>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-4.0.0.0" newVersion="4.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Castle.Windsor" publicKeyToken="407dd0808d44fbdc" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-3.2.0.0" newVersion="3.2.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.5.0.0" newVersion="4.5.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Microsoft.Owin.Host.SystemWeb" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-1.0.0.0" newVersion="1.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Castle.Core" publicKeyToken="407dd0808d44fbdc" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-3.2.0.0" newVersion="3.2.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
    <contexts>
      <context type="GdpSoftware.Server.Data.GdpSoftwareDbContext, GdpSoftware.Server.Data" disableDatabaseInitialization="true">
        <databaseInitializer type="System.Data.Entity.MigrateDatabaseToLatestVersion`2[[GdpSoftware.Server.Data.GdpSoftwareDbContext, GdpSoftware.Server.Data], [GdpSoftware.Server.Data.Migrations.Configuration, GdpSoftware.Server.Data]], EntityFramework" />
      </context>
    </contexts>
  </entityFramework>
</configuration>

回答1:

I needed to change by defaultConnectionFactory to be SqlConnectionFactory instead of the default

<entityFramework>
  <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework">
    <parameters>
      <parameter value="<My Connection String>" />
    </parameters>
  </defaultConnectionFactory>
</entityFramework>

http://blogs.msdn.com/b/davidobando/archive/2012/08/14/changing-ef-s-default-provider-from-localdb-to-sql-server.aspx

回答2:

Do the following in the App.config file,

1. Put the connectionStrings element is after the configSections element.
2. Put the startup element after the connectionStrings element.

<?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <configSections>
         <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=4.3.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
   </configSections>
   <connectionStrings>
         <add name="SchedulingContext" connectionString="Data Source=XXX\SQL2008R2DEV;Initial Catalog=YYY;Persist Security Info=True;User ID=sa;Password=XXX"   providerName="System.Data.SqlClient"/>
   </connectionStrings>
   <startup>
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>       
 </configuration>

回答3:

I Found that removing the references to Entity Framework and installing the latest version of Entity Framework from NuGet fixed the issue. It recreates all the required entries for you during install.

回答4:

I have broken my head over this issue, and finally here's what worked for me:-

Step1 : Uninstall Entity framework using Nuget package manager

Step2: Delete Entityframework element from App.config

Step3: Reinstall desired version of Entity Framework.

Step4: delete Migrations table and Migrations folder.

Step5: Enable Migrations and Add Migration and Update database

回答5:

I had multiple providers specified in my web.config.

 <providers>
      <provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices, MySql.Data.Entity.EF6" />
      <provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices, MySql.Data.Entity.EF6, Version=6.9.6.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d"></provider>
    </providers>

I simply removed one of those and it worked.

I am using MySQL though, not TSQL

回答6:

I ran into this issue when I forgot to set my Connections.config file to "copy always"

BareMessage = "Unable to open configSource file 'Connections.config'."

回答7:

I think the problem is from this line:

<context type="GdpSoftware.Server.Data.GdpSoftwareDbContext, GdpSoftware.Server.Data" disableDatabaseInitialization="true">

I don't know why you are using this approach and how it works...

Maybe it's better to try to get it out from web.config and go another way

回答8:

If you are maintaining one more cinfiguration file for app.config , Don't include any key in parent page.

Parent Page : app.config

<appSettings configSource="appSettings.config">
    <add key="ClientSettings" value="venice" /> <!-- Don't add Key Here -->
</appSettings>

Child Page : appSettings.config

<appSettings>
  <add key="ClientSettings" value="venice"/> <!-- add Here -->
</appSettings>

回答9:

I had same problem. After one day, I got it.

Problem was from adding two smtp tags in mailSettings under <system.net>.

回答10:

Search in your web.config or App.Config if you have some tags that are not used in your project or you don't have in your references.

回答11:

I had this error today on a nested MVC application running as virtual folder in onother MVC application. In my case the InnerException was more informative than the main one. It was stating:

- The entry 'DbContextMain' has already been added. (C:\inetpub\...\web.config line x)

After fixing the duplicate connection strings in the nested apps everything worked fine.

回答12:

If you use ASP.NET and IISExpress go to "C:\Users\\Documents\IISExpress\config\applicationhost.config", search for your Project and look if you have a faulty virtualDirectory entry.

回答13:

I faced similar issue and changing defaultConnectionFactory to be SqlConnectionFactory helped me solve it.

回答14:

actual error thrown Message=Unrecognized element 'providers' in web.config so from the web.config file remove the providers section

回答15:

The general issue is just any issue involving Machine/Web/App configs.

I had the same connection strings in Machine.Config as in my App.Config so I put before my first connection string in my App.Config

回答16:

This weird error happens, when you play around with different versions of EntityFramework versions in Nuget Packages like I did.

First, Uninstall your Entity Framework DLL from NuGet packages and then Clean up app.config. By removing the entry from configSections and entity framework element.

Next, install the desired version. This should fix the problem.

回答17:

I also faced the same issue, however in my case my solution has a console application and EF class library which mainly interacts with database. I removed Config settings related to EF from the Console Application Config. I maintained the following configuration settings in EF class library i.e only at one place.

This worked for me.

---

<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.2.61023.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />

<add name="EntityModel" connectionString="Server=Localhost\SQLEXPRESS;Database=SampleEntities;Trusted_Connection=True;" providerName="System.Data.EntityClient" />

---

回答18:

In connection string, the first string is the base in web.config

SchedulingContext is the base parameter of Entity file.

<connectionStrings>
     <add name="SchedulingContext" connectionString="Data Source=XXX\SQL2008R2DEV;Initial Catalog=YYY;Persist Security Info=True;User ID=sa;Password=XXX"   providerName="System.Data.SqlClient"/>