The downgrade of ipad3 to 8.4. 1 makes no sense. It's best not to downgrade, it's risky. When the ipad you bought is turned on, the system version is the most suitable version. Of course, the official will give you a new version later to remind you to upgrade. You can choose whether to upgrade according to your own needs. Generally speaking, as long as the official pushes information to you, it means you can upgrade. However, downgrading after upgrading will make ipad3 unusable, so it is meaningless.

The impact of ipad3 downgrade

Downgrading the Apple system is risky. Apple's official explanation is that in order to prevent devices from being downgraded to a software version that lacks the latest security updates, iOS uses a process called system software authorization. If the downgrade is allowed, attackers who physically touch the device will be able to install the earlier version of iOS and take advantage of the fixed security vulnerabilities in the new version of iOS.