Entity Framework 5 и Amazon RDS - Основният доставчик се провали при отваряне.

Проблемът беше в низа за връзка. По-конкретно, имах свойства „Име на приложение“ и „Приложение“ там. След като ги премахнах, проработи.

ЛОШО:

<add name="MyDbEntities" connectionString="metadata=res://*/MyDb.csdl|res://*/MyDb.ssdl|res://*/MyDb.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=MyDbServer;Initial Catalog=MyDb;Persist Security Info=True;User ID=MyDb;Password=MyPassword;Application Name=MyDb.API.Models;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />

ДОБРЕ:

<add name="MyDbEntities" connectionString="metadata=res://*/MyDb.csdl|res://*/MyDb.ssdl|res://*/MyDb.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=MyDbServer;Initial Catalog=MyDb;Persist Security Info=True;User ID=MyDb;Password=MyPassword;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" />