Multiple features on Twitter experienced temporary issues Monday, as users reported problems with broken links, images and at least one third-party app.
The affected features appeared to rebound back to normal about an hour after the outages were first reported.
Users said that when they clicked on a link posted to Twitter, they were shown a black window with text that read, "Your current API plan does not include access to this endpoint." The same message appeared when a reporter tried to use TweetDeck, a third-party platform that connects to Twitter accounts.
The phrase "Twitter API" began trending as the issue began affecting users.
NBC News observed a steep drop in user visits to news articles from Twitter starting just before 11:45 a.m. ET. The ability to embed tweets into NBC News articles also appeared to be disrupted.
Some users also reported issues viewing or uploading images. NetBlocks, a digital watchdog organization that tracks internet outages, tweeted confirmation that Twitter was experiencing widespread issues.
"Confirmed: Twitter is currently experiencing international slowdowns and outages affecting many users, also impacting image and video content; incident not related to country-level internet disruptions or filtering #TwitterDown," NetBlocks tweeted.
Twitter Support tweeted that some features were "may not be working as expected right now."
"We made an internal change that had some unintended consequences," it said. "We’re working on this now and will share an update when it’s fixed."
Elon Musk, Twitter’s owner and CEO, tweeted that the issues would be fixed.
"This platform is so brittle (sigh). Will be fixed shortly," he tweeted in response to another user.
Musk later added: "A small API change had massive ramifications."
Users were temporarily unable to post to Twitter last month in what was considered the most widespread outage since Musk took over the platform.
Musk reached a deal in April to buy Twitter for $44 billion but didn't officially take control until October. The company conducted layoffs almost immediately, terminating roughly 3,700 employees just days later.