error 0152: No Entity Framework provider found for the ADO.NET provider with invariant name"___" Make sure the provider is registered in the 'entityFramework' section of the application config file. See http://go.microsoft.com/fwlink/?LinkId=260882

I am writing a custom EF6 provider.I am able to connect to a database and also see the tables and all after making changes in app.config.

While using the functionality of Generate Database from model I am getting Null reference exception in GetAlldAssociationSets() On debugging my ssdto___.tt file I found that I get the above error in CreateStoreItemCollection(). How can I resolve this error. If EF was not registered properly , in app.config file or machine.config, then shouldn't I get an error while connecting to the database?

I have registered my Data Provider in GAC and also my EF provider in GAC.

What all steps could I try to resolve this error?