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

Possible solution is described in this Code Project tip:

As folks mentioned IIS user network service user credentials while trying to log in sql server. So just change the Application pool settings in your IIS:

1. Open Internet Information Service Manager
2. Click on Application Pools in left navigation tree.
3. Select your version Pool. In my case, I am using ASP .Net v4.0. If you dont have this version, select DefaultAppPool.
4. Right click on step 3, and select advanced settings.
5. Select Identity in properties window and click the button to change the value.
6. Select Local System in Built-in accounts combo box and click ok. That's it. Now run your application. Everything works well.