Entity Framework The underlying provider failed on Open

Question

Below is my connection string:

connectionString=\"metadata=res://*/EDMX.Test.csdl|res://*/EDMX.Test.ssdl|res://*/EDMX.Test.msl;provider=System.Data.Sq

Answer 1

We had connection string in web.config with Data Source=localhost, and there was this error (MSSQL was on the same machine). Changing it to actual `DOMAIN\MACHINE' helped, somewhy.