Update: We added a fix for this problem in a YouTube video below and updated the story.
The 'black dot' bug is the nickname of the latest glitch to plague Apple's iPhone and iPad operating system, and all it takes is a simple text message with two emoji.
Specifically, the offending emoji string consists of a 'medium black circle' between a less than and greater than symbol, and a leftward pointing finger (officially known as 'backhand index finger pointing left' in the emoji dictionary).
Getting a text message with these characters will freeze your Messages app, even if you try to quit the application and open it back up again. It'll open to the last text you viewed, which contains the string. It's a vicious cycle.
The reason for this problem? There are thousands of invisible Unicode characters that are a part of this emoji string, according to 9to5Mac, and it overclocks the CPU trying to process them.
How to fix this iOS 11 problem
To be fair, this is a glitch that has been demonstrated on Android phones and the Mac, but it's Apple's mobile operating system that seems to be crash the entire Messages app without a simple reset option.
A fix has been discovered, thankfully, care of EverythingApplePro. Using 3D Touch on home screen's Messages app icon, you can select 'New Messages' and avoid opening up the latest message with the problematic emoji.
From there, immediately delete the black dot message. Swipe left from the main Messages menu to reveal the delete button. If you click on the message, your app will freeze indefinitely again.