Entity Framework Error in Access VBA - "The specified named connection is either not found in the configuration..." - vba

Question

I have an Access VBA project from where I refer to a COM Interop .TLB written in C#. This C# code simply queries the SQL Server database and returns values via a simple LINQ-to-Entity query.
I'm getting the same error mentioned in this question:
The specified named connection is either not found in the configuration, not intended to be used with the EntityClient provider, or not valid
However, in my case, it is a Access VBA in a .ADP application that refers to my .Net 4.0 TLB, instead of another .Net project.
I'm aware that if it were another .Net project, I could add the EF connection string XML in its app.config or web.config. But what is the fix if my 'calling' application is Access 2003 VBA?
Here's the VBA code that calls the .Net code
Dim CandidatePassword As String
Dim abc As New MISHash.Password
Dim PasswordStatus As Boolean
CandidatePassword = InputBox("Enter your password")
PasswordStatus = abc.IsValidPassword("myusername", CandidatePassword) ' FAILS HERE
If PasswordStatus Then
MsgBox "Password valid."
Else
MsgBox "Password failed."
End If
Please help. Thank you.
Update: Here is my C# code
using System.Linq;
using System.Runtime.InteropServices;
namespace MISHash
{
public class Password
{
public Password()
{
}
[ComVisible(true)]
public void HashAndSave(string SomePassword)
{
string hashed = BCrypt.HashPassword(SomePassword, BCrypt.GenerateSalt(12));
//save the hashed password in the database
}
[ComVisible(true)]
public bool IsValidPassword(string CandidateUserName, string CandidatePassword)
{
string OriginalHashedPassword;
using (MyDBEntities mycontext = new MyDBEntities())
{
OriginalHashedPassword = (from usr in mycontext.Users
where usr.UserName.Equals(CandidateUserName)
select usr.Password).FirstOrDefault();
}
bool matches = BCrypt.CheckPassword(CandidatePassword, OriginalHashedPassword);
return matches;
}
}
}

Answer 1

See this similar question:
Can I use / access the app.config from .net code, when called via COM
These two seem like your best options:
Manually create a secondary AppDomain
Convert to a VSTO project
Edit
You can also try passing a hard-coded connection string in the constructor:
MyDBEntities mycontext = new MyDBEntities("Server=.\SQLEXPRESS;Database=School;Trusted_Connection=true;Integrated Security=True;MultipleActiveResultSets=True"))