anchor.diff:  ____
   
   == References
  +. https://msdn.microsoft.com/en-us/library/bb250462(v=vs.85).aspx
   . https://msdn.microsoft.com/library/ms536651(v=vs.85).aspx.
   . https://blogs.msdn.microsoft.com/ieinternals/2012/06/05/the-intranet-zone/
   
  
positive.code: ____
  
  
  And now, this issue can be resolved as the evironment issue.
  
  
  == Learned More
  
negative.code: 
  === IE Protect Mode
  
  After google "window.open() return null in IE" and there are many answers on stackoverflow mentions the _Protect Mode_.
  
  We just enable the _Protect Mode_ on virtual machine, it can not connect Facebook account and throw error "Popup could not open or was closed" like the QA'PC.
  
  _Protect Mode_ will cause `window.open()` return `null` as:
  
  [quote]
  ____
  