YouTube, the world’s biggest online video sharing and streaming service, said it restored service after engineers worked to address intermittent outages.

“We’re back! Thanks for all of your patience. If you continue to experience issues, please let us know,” YouTube, part of Google-parent Alphabet Inc., tweeted. The notice came just over an hour after an earlier Twitter post that acknowledged reports of trouble with YouTube, YouTube TV and YouTube Music.

We're back! Thanks for all of your patience. If you continue to experience issues, please let us know. https://t.co/NVU5GP7Sy6

— Team YouTube (@TeamYouTube) October 17, 2018

YouTube’s ad sales are a key revenue driver for Alphabet earnings, as seen in the latest earnings report. Still, inappropriate content on YouTube has become a headache for the business over the past year, as it struggles to contain the spread of disturbing content from its vast, decentralized creative community.

YouTube did not detail how widespread the outages with its services had been.