You can't downgrade your phone. You can install support files for iOS 16.4 to be able to debug your project on Xcode 12. Read the following article for more detailed information: https://www.swiftdevjournal.com/dealing-with-failed-to-prepare-device-for-development-error-message-in-xcode/

Create a Swift Playgrounds App project in Xcode if you want to use the project in the Swift Playgrounds app on iPad. You can find more detailed information in the following article: https://www.swiftdevjournal.com/working-on-a-swiftui-project-in-xcode-and-swift-playgrounds/

Before you trash Xcode 14.3, copy the iOS 16.4 support files to your Xcode 14.2 install. That will let you debug on your iOS 16.4 device with Xcode 14.2. You may find the following thread helpful: https://forums.macrumors.com/threads/xcode-14-2-14c18-breaks-with-ios-16-4-iphone-14-13-12-pro-iphonex-failed-to-prepare-device-for-development-after-os-ios-updates.2385046/ And you may find the following article helpful: https://www.swiftdevjournal.com/dealing-with-failed-to-prepare-device-for-development-error-message-in-xcode/

Don't store your Xcode projects on iCloud Drive. If you want an online backup of your projects, use version control and a service like GitHub, Bitbucket, or GitLab. The following article shows you how to put an Xcode project on GitHub, Bitbucket, or GitLab: https://www.swiftdevjournal.com/putting-your-xcode-project-on-github-bitbucket-or-gitlab/

Look into focused values and focused bindings. That's how menus in SwiftUI apps access the document. The following articles may help you: https://www.swiftdevjournal.com/accessing-the-document-in-a-swiftui-menu/ https://troz.net/post/2021/swiftui_mac_menus/

It appears your postMethodCall function takes three arguments: controllerName, actionName, and httpBody. When you make the call you have to place a colon, : after each argument name. You have commas after the controllerName and actionName arguments. Replace the commas with colons. APIWrapper.postMethodCall(controllerName: "juniorDoctor", actionName: "jnrsignup", httpBody: data) If that doesn't fix the compiler error, you will have to supply the signature of the postMethodCall function so we can see what the arguments are. For future reference, place your code listings in a code block instead of showing a screenshot of your Xcode window. Code in an image is much more difficult to read and can't be copied and pasted, reducing the chances of people answering your question.

Do you have a file named Models in your project? Or is this a new file someone else created and placed on GitHub. The answer to the following Stack Overflow question may solve your problem: https://stackoverflow.com/questions/29287734/how-to-pull-new-files-from-git-master

One potential problem with using Xcode for this project is the open source project may not support Xcode project files. You would have to create a new project in Xcode and add the files from the open source project to the Xcode project. You may have problems pushing your changes to the open source project because of the Xcode project file. If you use a text editor like Visual Studio Code, Sublime Text, BBEdit, or TextMate, you wouldn't have to deal with Xcode project files. If you decide to use Xcode, start by creating an External Build System project in Xcode. The External Build System project is in the Other section of the New Project Assistant. Creating an External Build System project will give you an Xcode project that uses make as the build tool if you follow the defaults. After creating the project add the files from the open source project to your project. You can either drag the folders in the project to the Xcode project or choose File > Add Files to ProjectName in Xcode.

If you want to make a game, I recommend using a game engine like Unity or Godot or using Apple's SpriteKit framework. Use a game engine if you want your game to run on non-Apple platforms. If you really want to use SDL in Xcode, start over by creating a new project. Your screenshot shows a command-line tool project. The problem with a command-line tool project on Mac is that it doesn't create an app bundle for the game. Creating an app bundle makes it easier to load graphics, sounds, and other files in your game code. According to the SDL Mac instructions on their GitHub page, https://github.com/libsdl-org/SDL/blob/main/docs/README-macos.md The Mac download of SDL includes Xcode project templates. Install the templates and use them to create the Xcode project. The link also has instructions on how to set up a new project by hand.

The error message is saying that the SDL2_image framework can't be found. For anyone to be able to help you, you must provide more information. List the steps you took to create the Xcode project and add the SDL frameworks to your project. Be very specific because the people on this forum aren't standing next to you. They can only go by what you write here. Not many people on this forum use SDL. You may have better luck asking this question in a game development forum where people use SDL.

Xcode 10.1 does not support SwiftUI. Xcode 11 is the earliest version that supports SwiftUI.

Someone asked a similar question yesterday. https://developer.apple.com/forums/thread/724901

It is definitely possible to avoid the sandbox in a Mac app. Perform the following steps to turn off the App Sandbox: Open the project editor by selecting the project file on the left side of the project window. Select the target from the left side of the project editor. Click the Signing & Capabilities button at the top of the project editor. Click the Trash icon on the right side of the App Sandbox section in the project editor. I don't know if you can avoid code signing. There is a Signing section above the App Sandbox section. That's where you would turn off code signing.

Use unlisted app distribution to limit an app to a select group of people. https://developer.apple.com/support/unlisted-app-distribution/

You are getting an error because displayLbl is an implicitly unwrapped optional whose value is nil. You declared the type to be UILabel!. By adding the ! character you set your app to crash if the outlet is nil and your code accesses the outlet. The most likely cause of the error is that the display label outlet is not connected to the label in the storyboard. Connecting the label in the storyboard to the outlet should fix that error. Your submitAction function also has the potential for the same error because you are force unwrapping optionals. When you add ! to a variable name, and that variable is nil, your app is going to crash. The following article has more details on dealing with the error you're getting: https://www.swiftdevjournal.com/fixing-the-thread-1-fatal-error-unexpectedly-found-nil-while-implicitly-unwrapping-an-optional-value-error/