title: EF Bug to add Tables
body: <p>I Can't find two tables to add on my Diagram.
  This is a bug or a feature?</p>
  
  <p><img src="https://i.stack.imgur.com/AunCM.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/MXG4s.png" alt="enter image description here"></p>
  
  <p><strong>----------------------UPDATE-------------------------------</strong></p>
  
  <p>I found the problem. 
  i don't know why, when I remove the tables of diagram these tables still there. Them it is a bug on VS.</p>
  
  <p><img src="https://i.stack.imgur.com/22cOR.png" alt="enter image description here"></p>