title: the user operation is waiting for background work to complete
body: <p>I am using eclipse junno for my IDE for developing android programs.</p>
  
  <p>my problem is just like this one :
  <a href="https://stackoverflow.com/questions/11514987/user-operation-is-waiting-for-building-workspace">User Operation is waiting for &quot;Building Workspace&quot;</a></p>
  
  <p>why did it happened and how can I solve this?
  I have waited lots of time about this case.</p>
  
  <p>right now it is look like this.</p>
  
  <p><img src="https://i.stack.imgur.com/RpSvt.jpg" alt="enter image description here"></p>