Your version is too old and Meta has deprecated it server-side. Fix: Uninstall the old WhatsApp (backup first) and install a newer compatible APK (e.g., v2.24.15.78).
Before WhatsApp stops working, export your chats: Chat > More > Export Chat (without media) to save important conversations. whatsapp free download for android 5.1.1
Updates frequently bring new features and improvements that enhance the user experience. Your version is too old and Meta has
Android 5.1.1, also known as Lollipop, is an older version of the Android operating system. Released in 2015, it was a significant upgrade to the Android platform, introducing a refreshed user interface, improved performance, and new features such as Device Protection and Quick Settings. Although it's no longer the latest version of Android, many devices still run on this operating system, and users may seek to download WhatsApp for their devices. Updates frequently bring new features and improvements that
Newer versions of Android and apps like WhatsApp often include patches for security vulnerabilities that have been discovered since the last update. This helps protect users' data from malicious attacks.