Why does the ‘Effective. Power’ text crash your iPhone?

Messages app crashing issue

Earlier in the week, we discovered that something as simple as a text could crash the iPhone.

Apple has published a temporary workaround on how to fix the issue and has promised a software update to fix it permanently. But we still get questions about why a text message with Arabic/Unicode crashes the iPhone.

So far the best explanation that I have come across is this one by a reddit user:

It only works when the message has to be abbreviated with ‘…’. This is usually on the lock screen and main menu of Messages.app.

The words effective and power can be anything as long as they’re on two different lines, which forces the Arabic text farther down the message where some of the letters will be replaced with ‘…’

The crash happens when the first dot replaces part of one of the Arabic characters (they require more than one byte to store) Normally there are safety checks to make sure half characters aren’t stored, but this replacement bypasses those checks for whatever reason.

Tom Scott, who runs a YouTube channel, has an another hypothesis as to why the text message crashes the iPhone, which he shares in the YouTube below. He speculates that unlike English, when you remove a character in Arabic in some cases it could result in the character becoming wider instead of becoming narrower, which could be the reason that is causing the crash.

It is just speculation so far, and we doubt Apple will provide the reason for the bug. If you’ve jailbroken your iPhone then install the IneffectivePower tweak to fix the issue.

If you have found a better explanation then please feel free to share it in the comments.