ios - Koloda delegate : fatal error: unexpectedly found nil while unwrapping an Optional value -

i using koloda in project , whenever try load 1 view controller in particular error "fatal error: unexpectedly found nil while unwrapping optional value" on kolodaview.datasource = self , if commented out same error on kolodaview.delegate = self. new ios , swift not sure going on. following code in koloda viewcontroller showing error:

 override func viewdidload() {     super.viewdidload()      kolodaview.datasource = self     kolodaview.delegate = self      self.modaltransitionstyle = uimodaltransitionstyle.fliphorizontal } 

the following code uiviewcontroller trying load. not linked via segues.

import foundation import uikit  class genderselection1: viewcontroller, uitableviewdelegate, uitableviewdatasource{     @iboutlet weak var tableview: uitableview!  override func viewdidload() {     super.viewdidload()     self.tableview.delegate = self     self.tableview.datasource = self  }   override func didreceivememorywarning() {     super.didreceivememorywarning()     // dispose of resources can recreated. }  // mark: - table view data source  func numberofsectionsintableview(tableview: uitableview) -> int {     return 2 }  func tableview(tableview: uitableview, viewforheaderinsection section: int) -> uiview? {      let  headercell = tableview.dequeuereusablecellwithidentifier("headercell") as! uitableviewcell     headercell.backgroundcolor = uicolor.grouptableviewbackgroundcolor()     return headercell }  func tableview(tableview: uitableview, heightforheaderinsection section: int) -> cgfloat {      return 1 }  func tableview(tableview: uitableview, numberofrowsinsection section: int) -> int {      return 1 }   func tableview(tableview: uitableview, cellforrowatindexpath indexpath: nsindexpath) -> uitableviewcell {     let cell = tableview.dequeuereusablecellwithidentifier("cell", forindexpath: indexpath) as! uitableviewcell      return cell }  func tableview(tableview: uitableview, didselectrowatindexpath indexpath: nsindexpath) {      tableview.deselectrowatindexpath(indexpath, animated: true)  } } 

kolodaview instance nil. verify putting nslog right after super.viewdidload().

nslog("kolodaview  \(kolodaview)"); 

i think, have not connected iboutlet properly. need check out.