An unhandled exception of type 'System.TypeInitializationException' occurred in EntityFramework.dll

Question

I was trying to learn Entity Framework and SQLite using this tutorial. However, I get an error.

The error thrown is:

An unhandled exception of type 'System.TypeInitializationException' occurred in EntityFramework.dll

Additional information: The type initializer for 'System.Data.Entity.Internal.AppConfig' threw an exception.

Here is the full error trace:

System.TypeInitializationException: The type initializer for 'System.Data.Entity.Internal.AppConfig' threw an exception. ---> System.Configuration.Configuration ErrorsException: 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\Ankur\Documents\Visual Studio 2012\Projects\ConsoleApplication1\ConsoleApplication1\bin\Debug\ConsoleApplication1.vshost.exe.config line 11)    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.Internal.AppConfig.get_DefaultInstance()    at System.Data.Entity.Internal.LazyInternalConnection..ctor(String nameOrConnectionString)    at System.Data.Entity.DbContext..ctor()    at ConsoleApplication1.ChinookContext..ctor()    at ConsoleApplication1.Program.Main(String[] args) in c:\Users\Ankur\Documents\Visual Studio 2012\Projects\ConsoleApplication1\ConsoleApplication1\Program.cs :line 16 

Here is the C# code:

namespace ConsoleApplication1 {     class Program     {         static void Main(string[] args)         {             using (var context = new ChinookContext()) //error comes on this line             {             }         }     }      class ChinookContext : DbContext     {     } } 

Here is file App.config:

<?xml version="1.0" encoding="utf-8"?> <configuration>   <system.data>     <DbProviderFactories>       <add name="SQLite Data Provider" invariant="System.Data.SQLite" description="Data Provider for SQLite" type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite" />     </DbProviderFactories>   </system.data>   <connectionStrings>     <add name="ChinookContext" connectionString="Data Source=|DataDirectory|Chinook_Sqlite_AutoIncrementPKs.sqlite" providerName="System.Data.SQLite" />   </connectionStrings>   <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>   <startup>     <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />   </startup>   <entityFramework>     <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">       <parameters>         <parameter value="v11.0" />       </parameters>     </defaultConnectionFactory>   </entityFramework> </configuration> 

Here is file packages.config:

<?xml version="1.0" encoding="utf-8"?> <packages>   <package id="EntityFramework" version="5.0.0" targetFramework="net45" />   <package id="System.Data.SQLite.x86" version="1.0.86.0" targetFramework="net45" /> </packages> 

Answer 1

Read the message:

Only one <configSections> element allowed per config file and if present must be the first child of the root <configuration> element.

Move the configSections element to the top - just above where system.data is currently.

Answer 2

Check which version of Entity Framework reference you have in your References and make sure that it matches with your configSections node in Web.config file. In my case it was pointing to version 5.0.0.0 in my configSections and my reference was 6.0.0.0. I just changed it and it worked...

<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false"/>