A recently discovered vulnerability with WhatsApp—and I use that term more loosely than usual, because this one doesn’t really seem like the app’s fault, per se—can lead to an incredibly frustrating crash loop if some stupid user sends you messages the app can’t handle.
We’ve seen this trick before: By dumping obscure characters into a message that WhatsApp doesn’t know how to process, a sender can crash a recipient’s app. But this isn’t a one-time joke; when you try to load WhatsApp, it will once again try to process characters it can’t handle, and crash again.
Since your WhatsApp chat history is tied to your device, not stored in the cloud, one quick way to fix this issue is to delete and reinstall the app. That’ll wipe your chats and get the app working again, but there’s the rub. Anything you haven’t previously backed up will be gone for good.
There is one more trick you can try if you’re encountering this issue, as reported by Tom’s Guide:
If you do receive one of these suspicious-looking messages, there’s a potential way to get rid of it safely. If you log into WhatsApp Web on a desktop or laptop computer, block the user who sent the message, then set your privacy to “My Contacts” or “My Contacts except..” and finally delete the message, you will have escaped a potential issue.
However, this only works if you already have a WhatsApp Web session open, so it’s not a solution if your app’s already crashing and can’t access the menu that lets you set one up.
Were I you—and I was a rabid WhatsApp user—I might go ahead and set up a web session right now just in case. It takes less than one minute to do, and by checking the “Keep me signed in” box, you should be able to access WhatsApp from your computer browser without issue until WhatsApp drops a patch for this issue. (I’m sure that’s on the way.)
Otherwise, make sure you’ve been backing up your WhatsApp chats to Google Drive or iCloud. I’d go do that right now, in fact, and then set a regular backup frequency so you don’t lose your chats for any other strange reasons in the future. You can never be too careful!