Question

I have a class library with EF Code First. I just upgraded to EF 4.3 and now I want to enable migrations.

I type Enable-Migrations -ProjectName MyProjectName in the PM console but receive the following error

PM> Enable-Migrations -ProjectName MyProjectName
System.Collections.Generic.KeyNotFoundException: The given key was not present in the dictionary.
   at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at System.Data.Entity.Migrations.DbMigrationsConfiguration.GetSqlGenerator(String providerInvariantName)
   at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration, DbContext usersContext)
   at System.Data.Entity.Migrations.DbMigrator..ctor(DbMigrationsConfiguration configuration)
   at System.Data.Entity.Migrations.Design.MigrationScaffolder..ctor(DbMigrationsConfiguration migrationsConfiguration)
   at System.Data.Entity.Migrations.Design.ToolingFacade.ScaffoldRunner.RunCore()
   at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.Run()
The given key was not present in the dictionary.
PM> 

I cant figure out what dictionary that might be wrong.

My connection string looks like this:

<connectionStrings>
  <add name="MySystem" connectionString="Data Source=MyServer\Instance;Initial Catalog=myDbName;Integrated Security=True" providerName="System.Data.SqlClient" />
</connectionStrings>

Any idea about what might be wrong?

Just a note:
I use my class library in a console application with an exact copy of my app.config and there I can access my database perfectly well.

Answer 1

It turned out Anders Abel was right in the cause, but we found a much simpler solution.

According to the mvc-mini-profiler page there is a special package in Nuget called MiniProfiler.EF that does not requires any wrapper around the SqlConnection. We dropped our old mvc-mini-profiler and installed the MiniProfiler.EF. Then Enable-Migrations worked as expected.