Hello claes178,
Thank you for reaching out to Apple Support Communities.
If the pages app isn't working as expected, let's review these steps:
"If an app on your Mac does not work as expected, try this.
1.Quit and reopen the app
Quit the app, then open it again. If the app won't quit, force the app to quit. Then check to see if the problem with the app is fixed.
2.Restart your Mac
Restart your Mac. Then check to see if the problem with the app is fixed.
3.Check for updates
To see if updates are available for the app, open the App Store, then click Updates. If updates aren't available for the app, update the software on your Mac. Or if you didn't get the app from the App Store, look for updates to the app on the app developer's website. Then check to see if the problem with the app is fixed.
4.Reinstall the app
Delete the app. When you do this, you might lose data that was stored in the app. Then redownload the app. If you didn't get the app from the App Store, redownload the app on the app developer's website. Then check to see if the problem with the app is fixed."
Additional details can be found here: If an app on your Mac stops responding, closes unexpectedly, or won’t open
If the issue persists, it may be best to reach out to Apple directly.
You can do so by going to Get Support
Cheers!