title: CS0234: The type or namespace name '<namespace2>' does not exist in the namespace '<namespace1>.' (are you missing an assembly reference?)
body: <p>I have a project that is receiving the "The type or namespace '' does not exist in the class or namespace ''" error. I've seen a lot of solutions here but I haven't been able to solve my problem.</p>
  
  <p>I have a solution with 2 projects, Web.Frameworks.Database and Web.Reports.OrderReporting.
  I am trying to reference the Frameworks.Database project in the Reports.OrderReporting.
  I have also confirmed both projects are compiling to the same framework (.NET Framework 4.5)
  Updated:  I have already added a reference to the project (in the Solution explorer).</p>
  
  <p>At this time, there is only one .cs file in the Frameworks.Database project, there's not much in it, it looks like this:</p>
  
  <pre><code>using System;
  using System.Data;
  using System.Web;
  using System.Data.SqlClient;
  
  
  namespace Web.Frameworks.Database
  {
      public class AccessDB : IHttpModule
      {
          /// &lt;summary&gt;
          /// You will need to configure this module in the Web.config file of your
          /// web and register it with IIS before being able to use it. For more information
          /// see the following link: http://go.microsoft.com/?linkid=8101007
          /// &lt;/summary&gt;
          #region IHttpModule Members
  
          public void Dispose()
          {
              //clean-up code here.
          }
  
          public void Init(HttpApplication context)
          {
              // Below is an example of how you can handle LogRequest event and provide 
              // custom logging implementation for it
              context.LogRequest += new EventHandler(OnLogRequest);
          }
  
  
  
          public void OnLogRequest(Object source, EventArgs e)
          {
              //custom logging logic can go here
          }
  
          #endregion
  
          public string ConnectionString;
  
          public string DumbLittleMethod()
          {
              return "This is my oh so fancy string.";
          }...
  </code></pre>
  
  <p>If I run this code through the debugger (F5 in Visual Studio), everything works fine.  But if I build my solution, and then access the page through Internet Explorer, that is when I get the error - for Line 11.</p>
  
  <pre><code>Line 9:  using System.Data;
  
  Line 10: using System.Data.SqlClient;
  
  Line 11: using Web.Frameworks.Database;
  
  Line 12: 
  </code></pre>
  
  <p>Any advice or tips would be appreciated. I've already spent a lot of time reading through similar questions, unfortunately with no success.  Thank you!</p>