Thanks, that worked! I knew it had to recompute somehow, but thought it was enough to just use the updateHorse() function. I ended up putting the recalculation at the end of the IBAction to keep it clean         if horseIndex < horseNumber {             horseIndex -= 1         }         if horseIndex == horseNumber {             horseIndex -= 1         }         if horseIndex == -1 {             horseIndex = horseNumber         }                  currentHorse = myHorses[horseIndex]         updateHorse()     }

That worked! Thanks very much :D

Fantastic! I ran into some trouble but found this - https://stackoverflow.com/questions/24924966/xcode-6-bug-unknown-class-in-interface-builder-file and now the tabs are all working! Now I need to see if I can reorder these tabs. Thanks very much for the help :)

Thanks for the clarification. I get the following: 2020-10-14 07:17:12.602493+0200 Tobiano[11289:1183798] [Storyboard] Unknown class HorseSettingsViewController in Interface Builder file. [<UIViewController: 0x7f80c9c21f30>, <UIViewController: 0x7f80c9d0b080>, <Tobiano.FeedPlanViewController: 0x7f80cb023800>, <Tobiano.TrainingViewController: 0x7f80c9f0bbf0>, <Tobiano.HorseViewController: 0x7f80cb016c00>] Could not cast value of type 'UIViewController' (0x7fff86e8caf8) to 'Tobiano.HorseViewController' (0x10eb13190). 2020-10-14 07:17:12.610662+0200 Tobiano[11289:1183798] Could not cast value of type 'UIViewController' (0x7fff86e8caf8) to 'Tobiano.HorseViewController' (0x10eb13190). Could not cast value of type 'UIViewController' (0x7fff86e8caf8) to 'Tobiano.HorseViewController' (0x10eb13190). CoreSimulator 732.17 - Device: iPhone 11 (A0DE279E-03DD-489A-BD23-29C452150AB1) - Runtime: iOS 14.0 (18A372) - DeviceType: iPhone 11

Do I type that into the debugger console? It gives me the following error when I do: error: unknown command shorthand suffix: '(tabBarVC.viewControllers)' I have no swift file for the UITabBarController because "Most clients will not need to subclass UITabBarController."

Yeah, it makes more sense to ask it to search for a UITabBarController :) How do I find the index for kIndexHorseViewController? For now, I tested it with "1" as the index and it crashed with the same error at let horseVC = tabBarVC.viewControllers![kIndexHorseViewController] as! HorseViewController

Maybe I should be using a navigation bar instead... I had to give it up last time because I wasn't able to put in UILabels in the header. I want to put in a back button, title, and UILabel with some status text. I'll look up some tutorials on navigation bars

Turns out it was just a bug. I copied the main view and pasted it, and deleted it again. The constraint errors disappeared on their own. As I worked through this app, the same issue came up a number of times and I fixed it this way

I solved this with a workaround: made a .xib file to place in the area where the header should be. Then I can add stacks and labels and everything.

As a side note though, is it possible to add a back button to a .xib like this? What I have used previously doesn't work:  Cannot find 'dismiss' in scope @IBAction func dismissVC(_ sender: Any) {          dismiss(animated: true, completion: nil)     }

Seems to be working now! This is great, thanks :)

I tried a few more things and now the header is showing, but I am unable to attach the outlets in the HeaderView.Swift to the elements in the HeaderView.xib. As long as the .xib is set to UIView, I can't attach anything to the code. I only get UIView in the assistant

I did a clean build folder, but still getting this error: Thread 1: "[<UIView 0x7fb6b0d119b0> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key headerText." I tried commenting out the bit where I change the headerText and the outlet for the header without result. Also checked for broken connections in the view controller. It's underlining AppDelegate in the error text with the same error. There is still a headerText outlet in HeaderView.swift. This isn't connected to anything since I changed the class of the HeaderView.xib, I can't see the file in assistant anymore so I deleted the connection. Still getting the same error

I wasn't able to send the link to the tutorial, but I changed the class of the .xib and now I get a new error: Thread 1: "[<UIView 0x7fdab4512fa0> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key headerText."

I think I solved the issue. I added an ID number to each new horse, making all the names unique. Now each new horse is random and also has an ID number. I made a property : var horsesCreated = 2 then each new horse got the property idNumber: (horsesCreated+1) and the buyHorseButton is assigned to do this after creating a horse; horsesCreated += 1 I know this maybe isn't the cleanest fix, but I am really happy it's working. Couldn't have done it without your input! Thanks for your patience :)