Although there was plenty of warning, the two-week grace period for WhatsApp on BlackBerry 10 is up and the app now no longer works. Those trying to use WhatsApp on BlackBerry 10 are now greeted with a 'Switch to a Supported Phone' message. If you still need to access WhatsApp, now is a great time to move into a BlackBerry KEYone or BlackBerry Motion where WhatsApp continues to be supported.
At this point, even exporting your existing data from WhatsApp for BlackBerry 10 has become a chore and the included Export to Android option found within WhatsApp for BlackBerry 10 remains a beta option and is less than reliable. Workarounds to keep WhatsApp working on BlackBerry 10 involve installing the Android version along with WhatsFixer but even then you're not getting the full experience of WhatsApp that moving to a supported device such as the BlackBerry KEYone or BlackBerry Motion will offer.