A group of fans have discovered an important vulnerability currently affecting WhatsApp that blocks the app by sending several thousand emoji in a conversation, with the only way to resume the chat with that particular user being to remove the entire chat history. The best way to resolve this problem is by updating the client to its latest version, as at the moment no other solution has been found.
As explained by the people who discovered the vulnerability, when you add a significant number of emoji (more than 6000) to a single message, the client destabilizes and ends up closing. This problem affects both the Android version and the web client in certain circumstances and takes place when sending from the latter. In the case of iOS, it seems like the app gets blocked, but it ends up working eventually.
Considering that during the festive season is when the service sees the biggest jumps in activity and that more than 1 billion people currently use the service, the gravity of the problem is enormous, as it offers a very easy way to force people to delete past chats. Our recommendation is that if you see a message in your notifications tab with an endless string of emoji, don’t open it, discard it, and don’t chat with that contact until the problem is resolved in coming updates.