The end of an era! WE WILL MISS YOU ANNOTATIONS! https://support.google.com/youtube/answer/7342737 …pic.twitter.com/vOur6MEnH2
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
But if I was YouTube, I'd 100% shut down annotations. It's a loss, but a minor one. And keeping it working, I'm sure, is significant work.
That was my main use for them, too. Now the only way to correct something is through comments or the description. Which isn't exactly effective.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.