SWIFT

dequeueReusableCellWithIdentifier returns nil

// You need to register the cell types with the tableview before it will return them
// Use either one of these depending on your setup

tableView.register(MyTableViewCell.self, forCellReuseIdentifier: "CellID1")
tableView.register(UINib(nibName: "yourNibName", bundle: nil), forCellReuseIdentifier: "CellID2")