I cant open documents in Pages or Numbers on iPad Os

Hello,

This is very strange!

Try resetting iPad's settings in Settings > General > Reset > Reset All Settings. Be certain you do not select Erase All Content and Settings as this will erase all of your information. It is a good idea to perform a backup of your iPad prior to resetting its settings.

Hello,

Do you receive an error message? Is your iPad running the latest versions of Pages and Numbers?

You are very welcome! It is also worth mentioning that Apple released an update to Pages, Numbers, and Keynote last night that may help prevent this from occurring to you in the future.