title: Updating user in Parse.com using Swift IOS8
body: <p>I am trying to get a user by objectId created in parse.
  After that, update that object by incrementing particular key. in this case "votes"</p>
  
  <p>I have tried the following code, and it succesfully gets the object then cast it to <code>PFUser</code> for updating but it throws an error during save in background claiming that the user has to be logged in or signed up yet it already has that user?</p>
  
  <p>Thanks for your help.</p>
  
  <pre><code>        var sender = self.mObject["sender"] as PFUser
          var senderObjId = sender.objectId
  
          println(senderObjId) //prints sender user object id
          //query the user
          var query = PFUser.query()
          query.getObjectInBackgroundWithId(senderObjId, block: { (object: PFObject!, error: NSError!) -&gt; Void in
  
              let user : PFUser = object as PFUser
              user.incrementKey("votes")
              user.saveEventually({ (success: Bool!, error: NSError!) -&gt; Void in
                  println(success)
              })
          })
  </code></pre>
  
  <p>SPECIFIC ERROR RECEIVED:</p>
  
  <pre><code>"NSInternalInconsistencyException" with reason "User cannot be saved unless `they have been authenticated via logIn or signUp":`
  </code></pre>