I am trying to declare some UI controls in Swift playground but the playground is throwing a error as invalid object. 

I think none of the UIKit elements are getting recognized. And I have tried creating a new project and adding the playground file but even this did not work out. The xcode version being used is 6.4.
I have already gone through these(links),
link1 and link2 but didn't really help me to solve this issue.
Can anyone help me out to solve the problem?
Thanks in advance :)
 
    