Windows 10 Mobile is now just a few weeks from its last cumulative update, and with the end of support, that means that things are about to stop working. One of those things is WhatsApp, which won't work beginning on December 31, as spotted by WindowsArea.de.
Right now, the app should still work on Windows 10 Mobile, and even Windows Phone 8.1, an OS that hasn't been supported since mid-2017. In fact, if you're still on Windows Phone 8.1, the Store will be completely shut down beginning on December 16. The Store will continue to work on Windows 10 Mobile after support ends on December 10, but obviously WhatsApp will be removed from it on December 31.
WhatsApp is also set to be retired for older versions of Android and iOS, although frankly, it's a bit surprising that these versions even still work. As of February 1, you'll no longer be able to use the service on Android 2.3.7 or iOS 7, both of which are versions that came out well over half a decade ago. Right now, Android 2.3.7 accounts for 0.3% of all Google Play devices, according to Google's most recent usage report.
As always, if you want to keep using WhatsApp, you'll need to upgrade to something newer. If you're still on a Windows phone, it's time to move to iOS or Android.