What version are you on? If it's not there in your appconfig, try running the script below against your DB. Please make sure to have a backup first, just in case.
Code:
INSERT [dbo].AppConfig(SuperOnly,Name,GroupName,Description,ConfigValue) values(1,'IsFeaturedCategoryID','SITEDISPLAY','The category ID that is considered to be ''Featured Products''. Products mapped to this category get a Featured status. The IsFeatured flag should also be set on the Product. This category ID provides an additional way for consumers to find the ''specials''. The ''is featured'' category Name typically has a Name like ''Specials'', ''On Sale Now'', ''Blowout Specials'', etc...','0');