This is often a codec issue. Older hardware decoders on the iPhone 4/iPad 2 struggle with newer VP9 codecs used by YouTube. Try switching the video quality to 360p or 480p within the app settings. High definition (720p/1080p) may cause stuttering or black screens on these legacy chips.

For a more stable experience on legacy devices like the iPhone 4, the community at

Downloading a working YouTube app for iOS 7.1.2—typically used on the iPhone 4—requires specific workarounds because the official App Store version now requires much newer software . You can either use a jailbreak-free method to get the last compatible version or use jailbreak tweaks to fix loading errors in older apps. ftp.bills.com.au Method 1: The Non-Jailbreak "Last Compatible Version"

If you previously downloaded YouTube on your Apple ID, you can still install a compatible version directly: