The site has been transitioned to version 3 and it is possible the older apps may no longer work. What version is your app?
If you want to find out for sure, you may want to open a ticket.
https://support.chess.com/customer/portal/emails/new
Cannot use app on older iPad 1
Sort:
Whenever I try to log in using the last supported chess.com app on iPad 1/iOS 5.1.5 I get a message saying the site is being upgraded and will be back shortly; but this is clearly not the case as the message has been popping up for weeks.
Please fix this problem. I was fine living without live chess functionality on the iPad 1 but the app is now completely unusable.