A mastering error has been discovered that affects select copies of Metalocalypse: The Complete Series DVD. The affected product is missing the special Metalocalypse: The Doomstar Requiem – A Klok Opera from one of the Season 4 discs. Unfortunately, a small quantity of product was sent to retailers before the issue was identified. Consumers who have purchased the title may contact WB Customer Support for a replacement disc at whv@warnerbros.com. Additionally, corrected product is currently being manufactured and will be shipped to retailers as soon as it is available.