Taking first plunge with collection views and am running into this error:
Terminating app due to uncaught exception \'NSInternalInconsistencyException
Just in case, if you are working with storyboard set collectionView identifier in the right place in the Attributes Inspector -> Identifier field. Not under the class name in "Restoration ID".
If you are using collection view in tableView cell, add delegates to tableView cell not in the tableViewController.