Error Unable to find the requested .Net Framework Data Provider. It may not be installed.

[Mikhail Filippov]

Hi all.
I'm install MySql Connector 6.7.4 over NuGet. I'm create connection string in App.Config:
<connectionStrings>
<add name="TodoContext" connectionString="server=localhost;uid=todo;database=todo;Pwd=xxxxxx;" providerName="MySql.Data.MySqlClient" />
</connectionStrings>
After run i'm get error: Unable to find the requested .Net Framework Data Provider. It may not be installed.
In this code:
var db = new TodoContext();
db.Todoes.Add(new Todo()
{
Text = "Test task #" + new Random().Next(),
DueDate = DateTime.Now,
Priority = new Random().Next(),
CreateTime = DateTime.Now,
Description = "bla bla bla"
});
Error fire on Add line. Please help me resolve it problem.