ibboard, 
From #Tumblr: PSA: Tumblr Live Looks like this adblocking rule no longer works on Tumblr Live:
www.tumblr.com##nav > ul > li[title="Live"]
You now need:
www.tumblr.com##div[data-cell-id^="timelineObject:live_marquee:"]
Which is very close to what worked in June and August. - https://ibboard.tumblr.com/post/730272135310901248/psa-tumblr-live