Twitter now seems to be limiting the number of tweets you can send (if you're not paying Musk, maybe)?
Or maybe this is something else?
Twitter has always had limits on how many tweets you could post in a day, but it was always very, very high. https://help.twitter.com/en/rules-and-policies/twitter-limits
Understanding Twitter limits | Twitter Help

Learn about account limits for things like API, updates, messages, and following, and find out why limits are used.

@parkermolloy I AM SO GLAD IT'S NOT JUST ME! I just got this error too, after only 15 tweets/retweets this afternoon (I counted). And there's no way to contact anyone to find out if it's an error or whatever and get it fixed, because the only way to contact anyone is through @TwitterSupport AND I CAN'T TWEET AT THEM.

Incredibly annoyed because most of my geographically local network is still using twitter exclusively.