Over the weekend, many X users noticed that older Twitter images had mysteriously disappeared from the site. Now, the company has confirmed that an unspecified “bug” is responsible and it’s working on a fix.

The issue first cropped up Saturday, when older tweets that had originally included images began to show as un-clickable t.co URLs instead. X now says the bug affected “images from before 2014,” but as The Verge previously pointed out tweets from 2014 — including the iconic Oscars selfie from Ellen DeGeneres — were also at least temporarily affected.

The 2014 Oscars photo has since been restored but other older tweets still seem to have missing photos for now. “We fixed the bug, and the issue will be fully resolved in the coming days,” X said in a statement via its support account.

X didn’t respond to a request for comment, or provide further details on the cause of the bug. The company said it hadn’t lost the underlying images or data. But it’s hardly the first time some aspect of the service has been disrupted over the last several months. Photos and links on the platform briefly broke in March as the result of API changes. The company was also recently caught slowing down links to a number of competitors and other websites run by entities Elon Musk has previously attacked. Musk has repeatedly complained about the state of X’s infrastructure, but has also drastically cut its budget for servers and laid off many site reliability engineers in an effort to reduce costs.