Isaac Smith

iPhone Says Unable to Update Calendars? 7 Fixes

A red exclamation mark under Calendars and nothing new for days. Seven fixes, starting with the Fetch schedule that waits for a charger.

Apple documents exactly two causes and the internet lists about eight. This separates the documented two from the four owners report.

Apple documents call forwarding for GSM service and sends CDMA customers to their carrier, which is why the row is absent on some lines.

Apple files error 1109 under network connectivity. Firewalls, DNS and the router are where the confirmed fixes are, not cables or parts.

If apps die seconds after you switch away, look for Fast App Termination under Developer settings. Two owners fixed it exactly there.

Check the EID on the About screen first, because it splits hardware from software. Older models hold one eSIM, so a filled slot removes the option.

The blocked list moved to Privacy and Security on iOS 26, blocked mail still lands in Trash, and a full block list fails silently.

On a dual SIM iPhone the switch is per line, and the emergency address step gates it. The rest is carrier provisioning, not Apple.

Apple lists four reasons for this message and only one is a counterfeit battery. One of the others is a repair that was never finished.

Find My shows four different messages, not two. One is a seven day expiry, one is a settings change, and one is not a problem at all.