Message=The provider did not return a ProviderManifestToken string.

Or, how to run EF code-first without SQL Express.

I got the above exception being thrown when I started playing around with Entity Framework’s Code-First CTP5. The inner exception revealed the true problem:

The problem is that by default EF Code-First tries to create your database on a SQL Express instance.

I don’t run SQL Express, I run SQL Server Developer edition. The solution is to add a connection string for the code-first database to your web.config (even though this database doesn’t yet exist):

<connectionStrings>
 <add name="TweetContext" connectionString="Data Source=.; Initial Catalog=Tweet; Integrated Security=SSPI;" providerName="System.Data.SqlClient" />
 </connectionStrings>

Note that the name (TweetContext) must match the name of your class which derives from DbContext, i.e.

public class TweetContext : DbContext

And you have to specify the DB name, i.e Initial Catalog=Tweet, but that database should not already exist, as EF code-first will create it for you.