I'm going through Cocoa programming for Mac OS X 3rd ed. I'm currently trying to do the sample app in chapter 11 - core data app. It's a very short chapter and everything seems straight forward but I must be missing something. First of all I drop the array controller into my objects. I then need to bind the managedObjectContext of the arraycontroller to the managedObjectContect of the Files owner. This is illustrated in pic 11.3 but for me it won't autocomplete and if I type it in manually I get a warning symbol on the right hand side of the text field indicating that things aren't working properly. Simply ignoring this for the time being isn't really working either as later on I must bind to the 'Car' entity but that is not showing up either. If feels like there is something missing, I feel like I should do something else to the arraycontroller... I'm using xcode4, could it be that the document template has changed since the book was published? Could someone who has the book and is a bit more familiar with arraycontroller have a look at the first couple of pages in chapter 11 and see if the process is still correct using xcode4. thanks!