EF Exception: An unhandled exception of type ' System.InvalidOperationException ' occurred in mscorlib.dll

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{"Unable to load the Entity Framework provider type registered in the application configuration file for an ADO provider with fixed name" System.Data.SqlServer " System.Data.Entity.SqlServerCompact.SqlCeProviderServices, Entityframework.sqlservercompact. " Make sure that you use the name of the qualified assembly and that the Assembly is available to the running application. For more information, see http://go.microsoft.com/fwlink/?LinkId=260882. "}

Workaround: Add a EntityFramework.SqlServer.dll reference to your Web project

EF Exception: An unhandled exception of type ' System.InvalidOperationException ' occurred in mscorlib.dll