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----------------------------[ UPDATE ]--------------------------->

I solved the issue by adding the connsectionString tag to the app.config in the executable project (not in the app.config inside the DataLayerAccess project) and it works fine.

Do you think I should opt for a different procedure?

I want to connect my application to my DB and I created the connectionString tag with all the info in the app.config file inside my DataAccessLayer. When I run the


I get a "Not set to an Object instance" exception referring to the ConnectionString.

I think it depends on having multiple app.config files within my application, for it's composed by multiple projects of type Library (one for each layer: dataAccess Layer, Business Logic Layer...).

How can I solve this issue and select the only app.config file I need?

What I have tried:

// the connectionString section in THE application config file I wanna use:

  <add name="DbNameConnection"
      connectionString="Data Source = nameOfTheHost; User ID = custom_user; password = 
      myPassword; Initial Catalog= name_Of_The_DB;/>

// My DB.cs class file in the DataAccessLayer:

public static string ConnectionString  
       string connStr =  ConfigurationManager.ConnectionStrings["DbNameConnection"].ToString();  
Updated 10-Nov-20 10:56am

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