YouTube users have been complaining of issues with getting a black screen instead of having a video load up for a couple of days now, but the issue seems to be getting gradually fixed by Google. While reports have largely waned and this writer's personal testing across multiple devices, operating systems, and accounts yielded no problems, there are still others out there reporting the black screen issue happening to them intermittently. In some of these cases, users are able to fix the issue simply by refreshing the page. Google has yet to acknowledge the problem outside of the YouTube Support forums, where no new topics about the problem have been made in the last few hours as of 9 AM PT, at least. Reports of the problem started circulating around the 1st of November, spiked and became fairly widespread, and began to wane somewhere in the early hours of this morning.
The problem manifests as a simple black screen taking the place of the video you want to watch, no matter how long you wait. While many users are no longer reporting issues, the problem is still around and is seemingly still affecting some people as of this writing. A number of users tried refreshing the page and reported that this fixes the issue, which could indicate that Google has set YouTube to somehow screen videos and fix the issue in real time as the video is being pulled from the server to be sent to a user's machine. This most likely means that Google has a handle on the situation and knows how to fix it, and is opting to implement that fix on a case-by-case basis rather than bringing the whole site down temporarily to apply a major fix. An alternative explanation is that Google has yet to start resolving the situation but that only some users are occasionally affected by the reported problems.
This is far from the first time that YouTube has experienced widespread issues, though Google usually takes time to make it known that the company is aware of any problems and is fixing them. The company does sometimes wait until after issues are fixed to post about them, just to let users know that it was made aware of any problematic occurrences, what happened, how it was fixed, and what the plan is to keep the same issue from happening again. Since the problem seems to be fixed for some users worldwide and Google has yet to post about it, that may be the case in this situation as well.