Tap the IPA in Filza → Install → Respring. YouTube will never expire.
Alternative (like Checkmate, Store!) to fix App Store downloads. How to Get YouTube on The First Gen iPad (iOS 5.1.1) Youtube Ipa For Ios 5.1.1
The IPA is trying to use a video decoder not supported. Go to Settings → YouTube → Quality → set to “Low” (240p/360p). iOS 5 cannot handle VP9 codec. Tap the IPA in Filza → Install → Respring
If you own a legacy device, do not throw it away. Grab a verified YouTube IPA, follow the steps in this guide, and enjoy a piece of mobile history. follow the steps in this guide