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>

How did you get the error trace? I need to see one for a similar problem I am having but cannot find it. — puser

Marc Gravell Marc Gravell · Accepted Answer · 2013-06-16T11:19:05

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.

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

6 Answers