A notable bug is causing your iPhone’s WiFi to break. The error is easy to cause but fortunately can also be repaired.

The error occurs when an iPhone connects to a network named ‘%p%s%s%s%s%n’. When that happens, the smartphone’s WiFi switches off automatically and remains unusable. This is also the case after restarting or naming the WiFi network. Connecting to other networks is then no longer possible.

Engineer Carl Shou discovered the flaw. He tells Bleeping Computer how he accidentally discovered the problem with his iPhone XS on iOS 14.4.2. Bleeping Computer was able to reproduce the error itself with an iPhone on iOS 14.4.6. The problem would not occur on Android.

The site suspects that the bug has to do with the % signs. The percent sign can be considered a variable name or a command in C and derived programming languages. As a result, the network name may not be interpreted as an ordinary string of characters. Whether the bug also works with other network names with percent signs is unknown.

At first, the problem doesn’t seem to go away when the WiFi network disappears. Still, it is relatively easy to get the WiFi on your iPhone working again without completely resetting the device.

All you need to do is restore your phone’s network settings. You can do this in the settings under ‘General’. You choose ‘Reset’ (reset), and you choose ‘Reset Network Settings’.

This will reset your network to factory settings. So you will have to log in again to previously known networks, but this way, you prevent your device from no longer working on WiFi.