Automatically click the "Show More" subscriptions button in the side bar
< YouTube - automatically expand subscription list 피드백으로 돌아가기
Hmm, it's still working for me. Try changing the code to say DEBUGGING=1 and then reload the page and check the console log messages (F12) to see what it says (look for messages beginning with ":::").
I heard YouTube is updating the site soon, possibly middle of March or April, so maybe you got an early update and I didn't. Also, I'm on Firefox, where as it look like you're on Safari, so things could be different there.
service
does not work