Xcode Doesn't Recognize My Device After OS Upgrade

This has to be a simple configuration issue, but I don't know my way around the build settings very well.

I upgraded my iPad from 4.3 to 5.0. I am using Xcode 4.2. When I plug my device in, it is not showing up on run button, and I have a message that it can't run using the selected device.

What do I have to do?

Which iOS version does Xcode 12.4 support?

Xcode 12.4 includes SDKs for iOS 14.4, iPadOS 14.4, tvOS 14.3, watchOS 7.2, and macOS Big Sur 11.1. The Xcode 12.4 release supports on-device debugging for iOS 9 and later, tvOS 9 and later, and watchOS 2 and later. Xcode 12.4 requires a Mac running macOS 10.15. 4 or later.

Open Xcode, go to Window -> Organizer and find your device. Click the "Use for Development" button to get Xcode to recognise it again.