title: Visual Studio 2015 WPF Project ToolBox Drag and Drop takes too long
body: <p>In Visual Studio 2015, I</p>
  
  <p>1- create or open a wpf project</p>
  
  <p>2- open a xaml file</p>
  
  <p>3- from toolbox drag anything (like button) to the designer</p>
  
  <p>4- it takes about 15 seconds to drop it</p>
  
  <p>no problem after that.</p>
  
  <p>Anyone can help me fix that delay?</p>