title: ASP.Net / C# - missing an assembly reference
body: <p><a href="https://i.stack.imgur.com/ssxgU.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ssxgU.jpg" alt="enter image description here" /></a>
  Hi, I am a newbie in C# and visual studio. As Figure1 shown, I am trying to use the classes from other project in similar solution.</p>
  <p>For example: I try to write &quot;Using LibraryMS.Framework&quot; at UserDto.cs from &quot;LibraryMS.MasterSetup&quot;.</p>
  <p>And I get the following error message:</p>
  <p>&quot;the type or namespace name 'framework' does not exist in the namespace 'LibraryMS' (are you missing an assembly reference?)&quot;</p>
  <p>Does anyone know how can I solve this?
  Also, do you have any good ASP.net website development online tutorial?</p>
  <p>Visual studio version: 2010
  .Net Framework 4.0</p>
  <p>Thank you.</p>