Users of videoconferencing platform Zoom were reporting problems hosting and joining meetings on Sunday. “Our team is investigating the root cause of issues joining Zoom Meetings. These issues appear to be limited to a subset of users,” according to an update on the company’s status page just before 10AM ET.

As of 11:39AM ET, the status page says users “should now be able to host, join, and participate in Zoom Meetings and Zoom Video Webinars if they restart their sessions. We will continue to assess this matter that impacted a subset of our users and monitor to ensure no further operational impact.”

A Zoom spokesperson didn’t provide a reason for the outage but said in an email to The Verge, “We sincerely apologize for any inconvenience this might have caused.”

Zoom users in the UK first began noticing widespread outages earlier today, although free accounts appeared to be functioning normally. Some churches have started using Zoom to hold virtual Sunday services during the coronavirus pandemic.

Overall Zoom usage has increased dramatically during the pandemic, and spotlighted the platform’s security issues, from “Zoombombingby trolls to an issue with Zoom’s “Company Directory” setting that could leak user emails and photos.

So far it’s not clear how widespread the outage was or what caused it.

UPDATED 11:55AM ET: Added Zoom’s latest update that the outage appears resolved

UPDATED 1:03 PM ET: Added comment from Zoom spokesperson