Download SmartTube Next.
Uninstalling and reinstalling the app worked for me.
You mean that's a loop? If so, try to force stop and erase all data. Do this action every time you have an error. Besides the loop, you might have the incorrect time and date. Switch them both to current. Check your wifi connection is correctly established. If none of this steps fixes it, consider reinstalling the YouTube app. If the error persists or any other app show also problems, your system has bug. In that case reset it to factory.
Disable YouTube, and sideload SmartTube (Stable version) instead.