I use a custom CollectionViewCell in my Storyboard. When I start the app I get this message:
Could not cast value of type \'UICollectionViewCell\' to T
You will get this error if you register your cell class both in Storyboard and in code. Choose one or the other, never both and the problem goes away.
I wish Apple didn't include this bit of code in their templates:
self.registerClass(SomeUICollectionCellClass.self, forCellWithReuseIdentifier: reuseIdentifier)
Especially since they always recommend you register your cells through Storyboard. Makes things very confusing.