Viber requires an SMS code. Old versions often throw "Connection Error."
If you still want to try, you generally cannot use the standard App Store. Users typically rely on these "grey-market" methods: How to install Viber on an iPhone 3G 4.2.1 firmware
After installation, go to > General > Profiles (or Device Management on some devices) and trust the Viber app. Viber .ipa for ios 4.2.1
Repositories like the "Untested Legacy iOS iPA Collection" often contain social networking apps compatible with iOS 3 and 4.
A custom firmware project that includes compatible app stores. ⚙️ How to Install Jailbreak: Use tools like Redsn0w or GreenPois0n . Viber requires an SMS code
One of the most requested apps for these older devices is . Unfortunately, modern Viber requires iOS 12 or later, leaving older devices in the cold.
Standard iOS 4.2.1 does not allow the manual installation (sideloading) of old .ipa files from third-party sources. Always back up your device before starting. Repositories like the "Untested Legacy iOS iPA Collection"
Official sources no longer host these files. You will need to find them in community-driven archives: