Terminating app: could not dequeue a view of kind: UICollectionElementKindCell with identifier - ios

Question

I'm implementing a custom .xib for a UICollectionViewCell and the app is crashing with:
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'could not dequeue a view of kind: UICollectionElementKindCell with identifier DaySelectorCell - must register a nib or a class for the identifier or connect a prototype cell in a storyboard'
There are several answers around that suggest that the identifier has a space in it or is missing. I've triple-checked everything though, and it's still throwing.
Here's my Storyboard config for the xib:
Here's my DaySelectorCell.swift class:
import Foundation
import UIKit
class DaySelectorCell: UICollectionViewCell {
#IBOutlet weak var dayOfWeekButton: UIButton!
var dayNumber: Int = -1
}
And my collectionView delegate implementation:
extension CustomViewController: UICollectionViewDelegate, UICollectionViewDataSource {
let days = ["M", "T", "W", "T", "F", "S", "S"]
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let id = "DaySelectorCell"
var cell: DaySelectorCell! = self.daySelector.dequeueReusableCellWithReuseIdentifier(id, forIndexPath: indexPath) as? DaySelectorCell
if cell == nil {
collectionView.registerNib(UINib(nibName: id, bundle: nil), forCellWithReuseIdentifier: id)
cell = collectionView.dequeueReusableCellWithReuseIdentifier(id, forIndexPath: indexPath) as? DaySelectorCell
}
cell.dayOfWeekButton.setTitle(days[indexPath.row], forState: .Normal)
cell.dayNumber = indexPath.row
return cell
}
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 7
}
}

Answer 1

If dan's answer doesn't work (and you already have registered the cell), do a clean, remove Xcode's build folder manually, quit Xcode, reboot the Mac and try again. Apple has done a very bad job with Xcode...