Twitter came back online for most users on Thursday morning after a global outage that left users unable to log in or access the social media app.

DownDetector, a site that tracks web outage reports, noted a spike among Twitter users around 8 a.m. ET. The site said that Twitter’s app, website and server connection appeared to be affected by the problem.

Twitter users attempting to use the site were logged out of their accounts, with many encountering error messages instructing them to refresh the page. The outage lasted about an hour, with users noting they were able to log back in around 9 a.m. ET.

“Gave me the option to log out or refresh. tried to log out and it said twitter was over capacity,” one Twitter user wrote.

“TWITTER WAKE UP I DONT LIKE THIS WAKE UP,” another user said.

Despite the trouble experienced by users, Twitter’s status page still noted that all of its systems were “operational.” The hiccup’s cause is still unclear.

Twitter representatives did not immediately return a request for comment.

In February, Twitter experienced a pair of sweeping outages that hindered user access for extended periods. The company later said it had addressed a “technical bug that was preventing timelines from loading and Tweets from posting.”

The latest issue arose as Twitter gears up for a legal battle with billionaire Elon Musk, who walked away from his $44 billion takeover deal with the company due to concerns about spam bots in its user base.

Twitter filed suit against against Musk this week in a bid to force the deal to proceed.