The Entity Framework provider type 'System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer' could not be loaded

Because the client application connects to WCF Services and is unaware of the existence of a database or data access layer, you do not need to install NuGet package for EF6 in the client application.

This mistake is caused by a deficiency inEntityFramework.SqlServer.dll in the host project's or service library's bin folder.

Choice 1

The simplest method is to install EF6 using NuGet Package Manager in your WCF Host project as well; if it has already been installed, try removing and reinstalling it. So as toEntityFramework.SqlServer.dll to generate directories

Please be aware that this approach may be in conflict with the n-layered requirements since your libraries above the data access layer are dependant on the less-than-ideal EF6.

Choice 2

To copy as a workaroundEntityFramework.SqlServer.dll Make sure output directories areCopy Local dll is configured totrue Afterward, add the following code to your DbContext constructor:

var ensureDllIsCopied = System.Data.Entity.SqlServer.SqlProviderServices.Instance; 

It guaranteesEntityFramework.SqlServer.dll is copied to the output directory of the data access project's consumers. This is an alternative.

By doing it this manner, the layers above the data access layer are not dependent on EF.