Because modern YouTube versions do not support iOS 10, you must download a "legacy" IPA that has been modified to work with older servers. YouTube++ (Legacy)
This repository contains a massive collection of YouTube versions for various iOS iterations. download youtube ipa file for ios 10.3.4
: Change both values to a modern version number, such as 15.10 , 17.03.2 , or even higher (e.g., 20.12.4 ). Because modern YouTube versions do not support iOS