The sign in button seems to be disabled.
iPad Wi-Fi, iOS 10.3.3
If it's greyed out check to see if you have Settings > General > Restrictions > Accounts (in the 'allow changes' section) set to 'Don't Allow Changes', if you do change it to 'Allow Changes'
How does the 'sign in' button look (I assume this is in Settings > iTunes & App Store), and what happens when you tap on it ? And have you tried closing the Settings app via the iPad's taskbar and re-opening it ?
Thanks. But, it isn't greyed out. I've changed the ID password and rebooted, and still can't sign in.
Can't sign in to App Store
