The "could not activate cellular data network" error means your iPhone won't be able to use the mobile data you're paying for ...

Make sure your preferred Outlook calendar is the one checked when you look here: Settings > Apps > Calendar > Default Calendar. Check the chosen calendar in the Calendar app. You may have been saving ...

Common causes include carrier outages, outdated carrier settings, corrupted network configuration, and SIM/eSIM provisioning errors.

Learn how to fix an iPhone stuck in SOS mode and restore your cellular connection quickly.