ASP.NET 5/EF 7: Could not load file or assembly 'System.Data.SqlClient'

[f0rt]

Hi team,

I'm deploying ASP.NET 5 application to Azure. After successful deploy and opening my site in the browser I'm getting the error:
FileNotFoundException: Could not load file or assembly 'System.Data.SqlClient, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.

I had similar issue using ASP.NET 4 explained here: http://stackoverflow.com/questions/21641435/error-no-entity-framework-provider-found-for-the-ado-net-provider-with-invarian
The solution named "the terrible hack" worked for me then. :)

Do you have any ideas what might be causing the problem and how to fix it?

Thanks in advance!

[f0rt]

System.Data.SqlClient is referenced in my project by EntityFramework.MicrosoftSqlServer. I've added direct dependency in project.json. My guess was that the dependency is not downloaded/deployed because it is not directly referenced. It failed again with the same error. I've added some code in startup.cs to prevent any deployment optimization (if exists) and the application crashed with "An error occurred while starting the application.".

[Sebazzz]

Having the same issue here in my application.

[Sebazzz]

This appears to be a duplicate of #3637.

[Sebazzz]

It appears that the real issue is a dependency problem of SqlClient which is being tracked in dotnet/corefx as #3760. Not sure what solution is possible in the mean time.

[f0rt]

It is strange but I have a dnx50 azure web job that is working with the same code. Glad to hear they're already working on that though. Thanks for the reply.

[Sebazzz]

That's odd.

I've just created a fresh VM on Azure with Ubuntu and I'm still having the issue:

System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> System.IO.FileNotFoundException: Could not load file or assembly 'System.Data.SqlClient, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.
       ---> System.IO.FileNotFoundException: Could not load the specified file.
         at System.Runtime.Loader.AssemblyLoadContext.LoadFromAssemblyName(AssemblyName assemblyName)
         at System.Runtime.Loader.AssemblyLoadContext.Resolve(IntPtr gchManagedAssemblyLoadContext, AssemblyName assemblyName)

Fixed that via #3689

[rowanmiller]

Closing as this is a dupe of #3637... which is actually an issue in DNX (a fix is being worked on at the moment).

https://github.com/dotnet/corefx/issues/3760 is actually a different issue which results in an exception about not being able to load the native assemblies (rather than System.Data.SqlClient).