ADO.NET provider with invariant name 'System.Data.SqlClient;' cannot be found (Entity Framework MVC)

Question

I cannot seem to resolve what appears to be a common issue with Entity Framework 6. I have reviewed the many topics related to this issue on SO, and am unable to find a solu

Answer 1

For me, this issue is caused by damaged EntityFramework. Uninstall EntityFramework as well as Visual Studio and Re-Installing the Visual Studio - The visual studio installation covers the .Net Framework SDK installation kind of resolved this issue.

Answer 2

You have this:

<add name="ReadContext" 
     connectionString="Server=Sql2014intsnace;Database=database;User Id=secret; Password=secret;" 
     providerName="System.Data.SqlClient;" /> <-- semi-colon

It should be this:

<add name="ReadContext" 
     connectionString="Server=Sql2014intsnace;Database=database;User Id=secret; Password=secret;" 
     providerName="System.Data.SqlClient" /> <-- no semi-colon

Otherwise, you're telling ADO to find a provider named System.Data.SqlClient; - there isn't one.

Answer 3

I got this error but for me, it was something entirely different. I was able to solve it by looking at only Unable to find the requested .Net Framework Data Provider and finding this answer.

I then had to edit:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\Config\machine.config

And:

C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\machine.config

Searching for DbProviderFactories both configs looked like this:

<system.data>
    <DbProviderFactories>
        <add name="IBM DB2 for i .NET Provider" invariant="IBM.Data.DB2.iSeries" description=".NET Framework Data Provider for IBM i" type="IBM.Data.DB2.iSeries.iDB2Factory, IBM.Data.DB2.iSeries, Version=12.0.0.0, Culture=neutral, PublicKeyToken=9cdb2ebfb1f93a26" />
    </DbProviderFactories>
    <DbProviderFactories />
</system.data>

When I removed the trailing <DbProviderFactories /> everything started working again.