SAN FRANCISCO (AP) — Twitter experienced widespread problems Wednesday as users who tried to post received error messages, the most serious outage in service since Elon Musk bought the platform in October.

It wasn’t immediately clear what caused the outage or if the issues were universal, but many users received an error message saying they were «over the daily limit for sending tweets.»

Other users said they could post if they scheduled their tweet to post later instead of immediately.

But some users said the problems were more widespread than trying to post, as they couldn’t access or send direct messages.

And when they tried to retweet someone else’s post, some users would get another error message: «Sorry! You’ve exceeded your tweet limit. Please try retweeting again tomorrow.»

Twitter does have a daily limit of 2,400 posts per day, according to its websitebut that is a ceiling that few users reach.

Twitter did not immediately respond to a request for information about the outage.

Musk buys Twitter for $44 billion and his subsequent decision to eliminate most of the company’s staff made predictions from the beginning that the infrastructure of the site could failBut those predictions had largely not come true before Wednesday.

Downdetector, a website that monitors social media complaints about online service interruptions, presented a sharp spike in Twitter complaints as of 5 pm ET.

NBC News was unable to send tweets from any of its accounts early Wednesday morning and received the tweet limit warning. A scheduled tweet sent through Tweetdeck, a popular Twitter client, worked.

This is a developing story. Please check for updates.