How do you update an old iPad that won’t update?

If you still can’t install the latest version of iOS or iPadOS, try downloading the update again:

1. Go to Settings > General > [Device name] Storage.
2. Find the update in the list of apps.
3. Tap the update, then tap Delete Update.
4. Go to Settings > General > Software Update and download the latest update.

14 Dec 2021