swift - How to respond to the error [Error]: Caught "NSInternalInconsistencyException" with reason "PFObject contains container item that isn't cached." -

to start off let me yes, question has been asked before, can't comment or ask question on pervious 1 i'm stuck it: how store dictionary on parse using swift? before continue let me give context error. iv'e been using parse ios app i'm making, , in screen 'a' make object, find corraponing group object in parse array stored in group object, add item array. , save parse. next on screen 'b' have table view grabs items , presents them. know there no problems screen 'b' because i've tested it. seems item not being added group object , frustrating. reason there error when click screen 'b' see if item saved [error]: caught "nsinternalinconsistencyexception" reason "pfobject contains container item isn't cached." if code im using save item seems failing here is. @ibaction func

addbuttontapped(sender: anyobject) {          if (itemname.text != "" && itemdescription.text != "") {              let newitem = item()             newitem.name = itemname.text!             newitem.descrpiton = itemdescription.text             newitem.gotten = false             newitem.rejected = false             newitem.sender = pfuser.currentuser()!.username!              let query = pfquery(classname: "group")              query.wherekey("objectid2", equalto: pfuser.currentuser()!.objectid!)              query.findobjectsinbackgroundwithblock { (objects, error) -> void in                 if error == nil && objects != nil{                     let obj = (objects as! [pfobject]).first!                      var items : [item] = obj.objectforkey("itemlist") as! [item]                      newitem.group = obj.objectid!                      items.append(newitem)                      obj.setobject(items, forkey: "itemlist")                     obj.save()                  }             }              itemname.resignfirstresponder()             itemdescription.resignfirstresponder()             bottomconstraint.constant = -140             itemname.text = ""             itemdescription.text = ""          }else{             }      }