Unable to find or load Npgsql with Entity Framework

Question

I am totally lost. In Visual Studio 2015, I created a WCF Library Service project and defined the service and service interface.

EntityFramework, EntityFramework.SqlSer

Answer 1

Problem solved. I neglected to add:

<system.data>
    <DbProviderFactories>
      <remove invariant="Npgsql" />
      <add name="Npgsql Data Provider" invariant="Npgsql" description=".Net Data Provider for PostgreSQL" type="Npgsql.NpgsqlFactory, Npgsql, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7" support="FF" />
    </DbProviderFactories>
  </system.data>

(See Visual Studio Support (DDEX)

Answer 2

uninstalling and reinstalling Npgsql.vsix resolved this problem.