title: SQL Server 2012 error: object reference not set to an instance of an object
body: <p>I use SQL Server 2012 and I have some databases on it. The problem is I suddenly get an error saying, </p>
  
  <blockquote>
    <p>object reference not set to an instance of an object</p>
  </blockquote>
  
  <p>I get this error when:</p>
  
  <ul>
  <li>Going to write a new query</li>
  <li>Select previously entered data by right click the table name ->
  Select top 1000 rows</li>
  </ul>
  
  <p>What I can do without getting error message:</p>
  
  <ul>
  <li>Log into my instance successfully using both Windows Authentication mode and SQL Authentication mode.</li>
  <li>Edit the table data by right click the table name -> Edit top 200 rows</li>
  <li>Create a new database</li>
  </ul>
  
  <p>I'm using:</p>
  
  <ul>
  <li>Microsoft SQL Server Management Studio: 11.0.3128.0</li>
  <li>Microsoft .NET Framework: 4.0.30319.34014</li>
  <li>Operating System: Windows 8.1</li>
  </ul>
  
  <p>Here are some snapshots of the error.
  <img src="https://i.stack.imgur.com/FLAUQ.jpg" alt="error"></p>
  
  <p><img src="https://i.stack.imgur.com/J5AFr.jpg" alt="Advanced_information"></p>
  
  <p>Please give me a solution to fix this problem. Your help will be highly appreciated.</p>