If your iPhone is on iOS 18, you also use an Apple Watch, and you tend to share watch faces with others through iMessage, you need to know about this very specific bug. And the fix, at least for now, could result in data loss.
So, what’s the bug? As reported by 9to5Mac, it involves replying in a threaded message with someone who shares a watch face with you from the Apple Watch.
The Apple Watch has a feature that allows users to easily share their customized watch face with someone else through Messages or Mail. The sharing feature is useful if someone wants your personalized watch face configuration, such as the complications or colors or what have you.
But right now, if someone shares a watch face with you, do not respond with a threaded reply. While those inline conversations can be useful for seeing what you’re responding to, doing so with a shared watch face will trigger a very unfortunate bug that will repeatedly crash the Messages app when attempting to open that chat.
This will make it very difficult to send or respond to other messages too, since it will repeatedly crash. The bug affects both users as well. Again, this only happens if you’re replying in a thread to a shared watch face and only if you’re running iOS 18.
If you are replying from iOS 18.1, currently in beta, it will not trigger the bug. However, if the other user not on iOS 18.1 responds to the shared watch face, the Messages app will crash on the iOS 18.1 beta, iPadOS 18.1 beta, and macOS 15.1 beta, too.
If you have encountered this rather weird bug, what’s the fix? Both users will have to delete the problematic conversation thread from their devices. But doing so is a bit difficult if Messages just crashes each time you try to use it.
This means that all conversation history needs to be removed from the device. This also includes all of your other chats, as well as any attachments that were not saved outside of Messages, like photos and video. Once all chat history has been cleared, do not attempt to restore the affected thread from deletion, as it will reintroduce the bug. You could try to restore from a backup, but since iMessage uses iCloud sync, that may be inefficient.
We should expect Apple to release a patch to the current public release of iOS 18 to address this issue. But for now, avoid replying directly to a shared Apple Watch face from others, at least until Apple issues a fix that doesn’t require losing years of chat history.