“This Twitter change today is a total dumpster fire,” James Spann, a meteorologist in Alabama, said on Twitter. “Unless something changes, this platform is now pretty much useless for those of us in the weather enterprise.”

A email to Twitter’s communications department seeking comment was returned with a poop emoji.

Since Mr. Musk’s takeover in October and his moves to eliminate more than 75 percent of the company’s work force, Twitter has become less stable, with features or the whole site sometimes going down without explanation.

On Saturday, engineers in the company raced to diagnose the problem in private Slack channels, according to two employees. Those people said that Twitter salespeople asked what they should tell their advertising clients as they realized that some ads were not being displayed on the social network.

Twitter’s U.S. advertising revenue for the five weeks from April 1 to the first week of May was $88 million, down 59 percent from a year earlier, according to an internal presentation obtained by The New York Times.

The company has regularly fallen short of its U.S. weekly sales projections, sometimes by as much as 30 percent, the document said.