Immediately following the installation of iOS 15 on my brand-new iPhone 13 Pro Max, I called my veterinarian and encountered the following strange error message:


I was able to make the call by pressing the "Call" button, but I was unsure of its significance. The problem recurred a couple more times when I attempted to call previously phoned individuals.

Why does the mistake occur?Here is the generally acknowledged cause for the "Last Line No Longer Available" problem, which typically affects iPhone models 11, 12, and 13. Instead of a physical SIM card, the phone attempts to access the iPhone eSIM (electronic Subscriber Identity Module). In the worst-case scenario, the iPhone owner is unable to make outgoing calls.
How to resolve the issue "Last Line No Longer Available"There are multiple solutions to the problem, so let's examine them one by one.
Purge the Call HistoryThis  Last line no longer available strategy was successful for me. In the Phone app, hit the Recents button (highlighted in red at left below), then tap the Clear button, followed by the Clear All Recents button.
This will delete your call log, so if there is anything you wish to keep, such as a phone number or the date/time a call came in, you may want to take a screenshot of it.
Remove and then replace the SIM cardSome users have had success by turning off the iPhone, removing the SIM card, waiting a minute or so, and then reinserting the card before turning the iPhone back on.
Use an official Apple SIM removal tool or a thin object like a straightened paperclip to remove the SIM card. Insert it into the SIM tray door's hole to open it. Remove the card, then replace it in the tray and retract the tray.

https://geeksnation.net/best-io-games