WhatsApp has announced a list of Android versions. Which will no longer WhatsApp Support in the phone from November 1st.
Some old versions of the phone are being gradually removed from the update of WhatsApp.

The update means that users using such devices will lose their chats. If their backup hasn’t been exported yet.
That likely leaves WhatsApp users with a security risk. Because Securities Patches expire.
WhatsApp by “No Longer Supports” means that WhatsApp application will no longer be updated.
That is, new features cannot be downloaded. This also leaves WhatsApp at greater risk of a securities break because secure features cannot be download.
Why is WhatsApp not working?
The developers of the software state that as of November 1, 2021, “WhatsApp will stop supporting phones running Android 4.0.4 or earlier.
We advise storing your conversation history before that date or switching to a supported device.
List of all phones will not WhatsApp support
Samsung | Samsung Galaxy Trend Lite |
Galaxy Trend II | |
Galaxy SII | |
Galaxy S3 mini | |
Galaxy Xcover 2 | |
Galaxy Core | |
Galaxy Ace 2 | |
LG | Lucid 2 |
LG Optimus F7 | |
LG Optimus F5 | |
Optimus L3 II Dual | |
Optimus F5 | |
Optimus L5 | |
ZTE | Grand S Flex |
V956 | |
Grand X Quad V987 | |
ZTE Grand Memo | |
Huawei | Ascend G740 |
Ascend Mate | |
Ascend D Quad XL | |
Ascend P1 S | |
Ascend D2 | |
Sony | Xperia Miro |
Xperia Neo L | |
Xperia Arc S |
As well as from Alcatel, HTC, Lenovo, and other devices.
Will not WhatsApp support in Apple devices as well?
There have been reports that some iPhones such as the iPhone 6 and 6s will be at risk of going out of WhatsApp support.
However, in a recent FAQ, WhatsApp says that people should use phones running Android version OS 4.1 or iPhone running iOS 10 and newer.
The change in operation came after WhatsApp experience it’s longest blackout earlier this month, with access blocked for six hours.