You cannot update WhatsApp to a working state on iOS 7.1.2. The old version is a museum piece—it installs but does not connect.
When she went to the App Store to download it again, she was met with a frustrating message: "This application requires iOS 10.0 or later." Her iPhone 4 only went up to iOS 7.1.2. whatsapp old version for ios 712 download upd
“This application requires iOS 10 or later. You must update to iOS 10 in order to download and use this version of WhatsApp.” You cannot update WhatsApp to a working state on iOS 7
: The protocols WhatsApp uses to send messages have changed multiple times since 2014. Old app versions do not know how to communicate with current servers. Security Risks “This application requires iOS 10 or later
, the core issue is server-side authentication, not just the app file itself. 1. The Hard Truth: Server-Side Expiration