The type initializer for 'System.Data.Entity.Migrations.DbMigrationsConfiguration`1' threw an exception

I am trying to Enable migration in Code first using Nuget package manager console command

enable-migrations

it is throwing this error, "The type initializer for 'System.Data.Entity.Migrations.DbMigrationsConfiguration`1' threw an exception".

Complete error details are:

System.TypeInitializationException: The type initializer for 'System.Data.Entity.Migrations.DbMigrationsConfiguration`1' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Data.Entity.Internal.AppConfig' threw an exception. ---> System.Configuration.ConfigurationErrorsException: Configuration system failed to initialize ---> System.Configuration.ConfigurationErrorsException: Only one <configSections> element allowed per config file and if present must be the first child of the root <configuration> element. (C:\Users\vks\Documents\Visual Studio 2017\Projects\CodeFirstDemo\CodeFirstDemo\tmp60AA.tmp line 10)
   at System.Configuration.ConfigurationSchemaErrors.ThrowIfErrors(Boolean ignoreLocal)
   at System.Configuration.BaseConfigurationRecord.ThrowIfParseErrors(ConfigurationSchemaErrors schemaErrors)
   at System.Configuration.BaseConfigurationRecord.ThrowIfInitErrors()
   at System.Configuration.ClientConfigurationSystem.EnsureInit(String configKey)
   --- End of inner exception stack trace ---
   at System.Configuration.ClientConfigurationSystem.EnsureInit(String configKey)
   at System.Configuration.ClientConfigurationSystem.PrepareClientConfigSystem(String sectionName)
   at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String sectionName)
   at System.Configuration.ConfigurationManager.get_ConnectionStrings()
   at System.Data.Entity.Internal.AppConfig..ctor()
   at System.Data.Entity.Internal.AppConfig..cctor()
   --- End of inner exception stack trace ---
   at System.Data.Entity.Infrastructure.DependencyResolution.DbConfigurationManager.EnsureLoadedForAssembly(Assembly assemblyHint, Type contextTypeHint)
   at System.Data.Entity.Infrastructure.DependencyResolution.DbConfigurationManager.EnsureLoadedForContext(Type contextType)
   at System.Data.Entity.Migrations.DbMigrationsConfiguration`1..cctor()
   --- End of inner exception stack trace ---

Here is my web.config file

<configuration>
  <connectionStrings>
    <add name="Default"
         connectionString="Server=localhost; Database=CodeFirstTest ; Integrated Security=True"
         providerName="System.Data.SqlClient" />
  </connectionStrings>
  <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" />
  </configSections>
  <appSettings>
    <add key="webpages:Version" value="3.0.0.0" />
    <add key="webpages:Enabled" value="false" />
    <add key="ClientValidationEnabled" value="true" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
  </appSettings>
  <system.web>
    <compilation debug="true" targetFramework="4.5.2" />
    <httpRuntime targetFramework="4.5.2" />
    <httpModules>
      <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" />
    </httpModules>
  </system.web>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" culture="neutral" publicKeyToken="30ad4fe6b2a6aeed" />
        <bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Optimization" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="1.1.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="WebGrease" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="0.0.0.0-1.5.2.14234" newVersion="1.5.2.14234" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false" />
    <modules>
      <remove name="ApplicationInsightsWebTracking" />
      <add name="ApplicationInsightsWebTracking" type="Microsoft.ApplicationInsights.Web.ApplicationInsightsHttpModule, Microsoft.AI.Web" preCondition="managedHandler" />
    </modules>
  </system.webServer>
  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.CSharpCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:6 /nowarn:1659;1699;1701" />
      <compiler language="vb;vbs;visualbasic;vbscript" extension=".vb" type="Microsoft.CodeDom.Providers.DotNetCompilerPlatform.VBCodeProvider, Microsoft.CodeDom.Providers.DotNetCompilerPlatform, Version=1.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" warningLevel="4" compilerOptions="/langversion:14 /nowarn:41008 /define:_MYTYPE=\&quot;Web\&quot; /optionInfer+" />
    </compilers>
  </system.codedom>
  <entityFramework>
    <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="mssqllocaldb" />
      </parameters>
    </defaultConnectionFactory>
    <providers>
      <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
    </providers>
  </entityFramework>
</configuration>

How to resolve it?

Asked by:- jaya

: 15712 At:- 7/29/2017 7:25:30 AM

C# web-config code-first-migration entity-framework

add comment to question

3 Answers

Answered by:- bhanu

You need to change the position of connection string in web.config, I had exact same issue when my <connectionString /> was on the top part of the Web.config, just after <configuration> ,then I tried to build proejct again, after moving it right before </configuration>, and it worked.

At:- 7/29/2017 1:08:19 PM Updated at:- 7/29/2017 1:08:41 PM

thanks the above solution helped me 0

By : jaya - at :- 8/5/2017 8:12:54 AM

comment to above answer

Answered by:- vikas_jk

There can be many causes of the issue, as the error already shows(System.Configuration.ConfigurationErrorsException), you can have issue in Config file, one is already mentioned in above comment. Another can be

One possible out of the way reason can be that, your project where the migrations are getting enabled can be different from the startup project. So be sure to add -StartUpProject to your NuGet command.
Version of the entity framework used can be different in case of two different projects.
Check if there is any issue like double connection string in web.config, with same name