as Apple has changed how Xcode is installed with version 4.3, we need to make some changes to App Studio to make the installation and export experience as smooth as possible.
Therefore currently we recommend to stay with Xcode 4.2.1, even if you are on Lion.
Here's how to find and install Xcode 4.2.1 for Lion:
- Uninstall Xcode 4.3
- Go to http://connect.apple.com/cgi-bin/WebObjects/MemberSite.woa/wa/downloads.
- Log in with your iOS Developer account credentials.
- In the Developer area on the right, click 'Developer Tools'.
- Scroll down to 'Xcode 4.2.1 for Lion' and download the installer.
- Run the installer. On my computer, it installed an app named 'Install Xcode.app' in my Applications folder.
- Run the 'Install Xcode.app' application. This installs Xcode in the /Developer folder.