How to Fix an iPad Activation Error
Some error messages are so vague that you might feel lost when trying to figure them out. This is the case with the iPad's "Could not activate" error, which interrupts the setup tablet's setup process. Fortunately, we've got a few things you can try to see if they fix your system.
If you've got a laptop (or desktop) lying around, you can use iTunes, but you'll need to update it first. On a Mac, open iTunes, click iTunes in the Menu bar, and click Check for Updates. On a PC, open iTunes, click Help and select Check for Updates.
After updating, attach your iPad to your laptop, and in iTunes, click the iPad icon that appears after connecting. Then, select "Set up as new iPad" or "Restore from backup." Next, follow the steps provided, including naming your tablet, and wait for it to be activated.
Perform a Hard Reset
If that doesn't work, and you have Wi-Fi, a hard reset may do the trick. Hold down the Home button and the Sleep/Wake button until the Apple logo appears (also known as the lock button), and follow the steps presented.
Dance Around Public Wi-Fi Constraints
If you're setting up your iPad from a public network that requires a login via the web, you're also facing the issue that the iPad doesn't allow you to use a web browser until it's set up. At the Wi-Fi network selection window, tap Next to decline using Wi-Fi.
Once you get to the home screen, tap Settings and Wi-Fi to find the network and sign in, and then tap iCloud in Settings to sign in over Wi-Fi.
Escape Developer Mode
The Activation error can also arise if your iPad is running a developer version of iOS. In these cases, you'll want to follow the iTunes instructions above, and choose Set up as new iPad.