Interestingly enough it seems that these error messages only display for the duration of the ad, which as VentureBeat points out, technically means that Adblock Plus is still doing its job in terms of blocking ads, but unfortunately this error message would also seem to suggest that users won’t be able to bypass the ads and go straight to the video.
According to Adblock Plus’ head of operations Ben Williams, “We’re looking into what the problem might be, but at the moment it would appear to be an issue on YouTube’s side. Let’s hope for a speedy solution.” Testing by VentureBeat also found that this seems to affect Chrome browsers with the Adblock Plus extension, and that browsers such as Firefox had no such issue.
It has also been noted that this issue appears to affect certain Google accounts, so some users have found success by switching accounts. We’re not sure if this is a bug with Chrome, or if Google or YouTube are starting to fight back against ad blockers.