If you have an old Android 5.0 device and want to watch a music video or a podcast in the background, the YouTube app is still usable—barely. However, for active daily use, commenting, or uploading, the app is a relic of a bygone era. It serves as a reminder of how "heavy" modern apps have become, but you wouldn't want to rely on it as your daily driver.
“There was a problem with the server [400]” youtube android 5 version full