The provider did not return a ProviderManifestToken string Entity Framework

In my case, it was my SQL Server instance that was not running. I simply started the service and everything worked fine. Hope this helps someone down the road.

I also faced to this error and I solve that downgrading these NuGet packages

MySql.Data - 6.9.12

MySQL.Data.Entity - 6.8.8

this is my reference URL which I referred

Well I fixed it.

Just needed to put "." for localmachine in the data source as follows:

<add name="MYSQLSERVER"
     providerName="System.Data.SqlClient"
     connectionString="Data Source=.\MYSQLSERVER;Trusted_Connection=true"></add>    
</connectionStrings>