If the official APK fails to load videos, these lightweight, third-party clients are often better suited for Lollipop devices:

Using a YouTube APK on Android 5.1.1 is a viable solution for breathing temporary life into a nostalgic or secondary device. The sweet spot—version 16.29.36—provides a robust experience without constant crashes.

Android 5.1.1 Lollipop—codenamed "Lollipop MR1"—was released by Google back in April 2015. While it was a revolutionary update at the time featuring Material Design and improved device performance, it has since been declared obsolete by most developers, including Google. In 2023, the official YouTube app from the Google Play Store no longer supports Android versions below 6.0 (Marshmallow).

Keep in mind that this version is outdated and may not work properly with modern devices or the latest YouTube features. For the best experience, I recommend using the latest version of the YouTube app from the Google Play Store.