Error: No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlClient'
.net, ado.net, c#, entity-framework, entity-framework-6
Solution
Ok, this is pretty weird. I have a couple of projects: one is a UI project (an ASP.NET MVC project) and the others are projects for stuff like repositories. The repositories project had a reference to EF, but the UI project didn't (because it didn't need one, it just needed to reference the other projects). After I installed EF for the UI project as well, everything started working. This is why, it added this piece of code to my Web.config:
<entityFramework>
<defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />
<providers>
<provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" />
</providers>
</entityFramework>
Problem
I recently upgraded/updated Entity Framework in an old project from version 4 or 5 to version 6. Now I get this exception: An exception of type 'System.InvalidOperationException' occurred in EntityFramework.dll but was not handled in user code Additional information: No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlClient'. Make sure the provider is registered in the 'entityFramework' section of the application config file. See http://go.microsoft.com/fwlink/?LinkId=260882 for more information. I googled the error and came across a couple of SO threads, but none of them contained a solution that works for me. This is what my App.config looks like: ``` <?xml version="1.0" encoding="utf-8"?> <configuration> <configSections> <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 --> <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" /> </configSections> <entityFramework> <defaultConnectionFactory type="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" /> <providers> <provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer" /> </providers> </entityFramework> </configuration> ``` I already uninstalled Entity Framework from my project and re-installed it, deleted all the references to old EF files and re-installed, but nothing works for me. I keep getting this error.