Postgresql and Entity Framework
The problem points to a wrong provider type or assembly name.
<entityFramework> <defaultConnectionFactory type="Npgsql.NpgsqlFactory, Npgsql" /> <providers> <provider invariantName="Npgsql" type="Npgsql.NpgsqlServices, Npgsql.EntityFramework" /> </providers></entityFramework>The assembly name is wrong. The assembly installed by the EntityFramework6.Npgsql package is EntityFramework6.Npgsql.dll. In fact, adding the package to a new project sets the correct provider line:
<providers> <provider invariantName="Npgsql" type="Npgsql.NpgsqlServices, EntityFramework6.Npgsql" /></providers>