EverythingApplePro has shared a new video showing how a simple set of emoji characters (<⚫> ??) can cause Messages on iPhone and iPad to freeze and become unresponsive.
The simple emoji string contains thousands of hidden invisible Unicode characters, and causes the Messages app to freeze and crash as it overloads the applications memory.
Apple hasn’t yet acknowledged the ‘Black dot’ bug, however; fingers crossed an update rolls out soon to fix this issue. In the meantime, if you’ve been sent the emoji string, you could try force-quitting the Messages application, and use 3D Touch to open a new conversation. You can then backtrack to the main Messages list and delete the conversation thread that contains the ‘Black dot’ emoji.