https://www.vox.com/2016/5/19/11701976/rapping-deconstructed-best-rhymers-of-all-time
Unblocked ad in video.
I can't reproduce, video plays without ads using Chrome or Firefox on my end.
I just tried in a new profile with only uBO with default settings and still got the ad. Here's my log:
uBlock₀ — Logger.zip
I clicked play on the video at 19:50:54
Sorry I still can't reproduce, somebody who can will have to fix this issue, if possible, which is not a given
with some video ads.
@gorhill @mapx- @SMed79 can any of you reproduce this?
Video plays instantly without ads for me too.
Can you try a US IP?
Can't reproduce.
new profile with only uBO with default settings
Did you force an update of the filter lists after install?
@gorhill Yes, I purged the cache and updated the lists. I just tried again on a new profile with only uBO installed with default settings, updated lists, and the pre-roll video ad still plays. I can offer you TeamViewer access to my computer if that helps.
@terrorist96 Use the logger https://github.com/gorhill/uBlock/wiki/The-logger
@SMed79 I did, see here.
Here's a screenshot:

The red line indicates where I played the video and the ad started.
I can reproduce using a us ip.
Could be brightcove unblockable ads ? (SSAI - baked in the stream)
It seems the video (but also the video ads) are broken in segments
xhr | https://once-aws-us-west-2-lb.unicornmedia.com/now/media/segment...
xhr | https://brightcove.vox-cdn.com/permutation/...
I'm having problem even playing the video, unless I disable uBlock. _(Firefox 54.0.1 (64-bit); uBlock Origin 1.13.4)_


@pepablock If you have privacy badger, you need to temporarily move these two to the yellowlist:
https://github.com/EFForg/privacybadger/issues/1512
Or click to see what filter list is blocking *.unicornmedia.com
@terrorist96 I don't use Privacy Badger.
You have Firefox's Tracking Protection enabled?
Edit: never mind, it works fine with Tracking Protection enabled. Something specific on your side is causing this, video plays fine with uBO + default settings/lists.
I had leftover enabled third-party list (hpHosts’ Ad and tracking servers​​​​​), when I disabled the filter everything was working as it should. My bad.
I can't reproduce this anymore.
Most helpful comment
It seems the video (but also the video ads) are broken in segments