ios - Xcode 7.3 - Unknown class <MealViewController> in Interface Builder file -

i'm beginner developer , i'm following getting started apple tutorial learn basics.

this "unknown class" has appeared in few other threads none of answers seemed fix problem time. checked references class , storyboard source code project builder/compile sources. keeps failing.

the breakpoint appears in part of code @ custom class mealtableviewcontroller.swift

    override func prepareforsegue(segue: uistoryboardsegue, sender: anyobject?) {                    if segue.identifier == "showdetail" {              let mealdetailviewcontroller = segue.destinationviewcontroller as! mealviewcontroller              if let selectedmealcell = sender as? mealtableviewcell {                  let indexpath = tableview.indexpathforcell(selectedmealcell)!                 let selectedmeal = meals[indexpath.row]                 mealdetailviewcontroller.meal = selectedmeal             }          }          else if segue.identifier == "additem" {              print("adding new meal.")         }     } 

the problem occurs when clicking cell in table view, have impression might have segue. i've checked against tutorial , see no difference.

i've uploaded entire project here. i'm trying upload git repo that's thing have learn.

any appreciated, i've run out of options on test heer.