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Mark Zuckerberg, chief executive officer and founder of Facebook Inc.. attending a Viva Tech launch and a technology gathering at Park des Expositions Porte de Versailles on May 24th, 2018 in Paris, France.
Facebook users around the world are reporting logs in and out-of-site, as well as Instagram and WhatsApp.
It's Downdetector's top problems with Facebook, a web site for users to report problems on apps and websites.
Facebook users posted pictures from Twitter showing error messages when they tried to download the app.
Previously Facebook had a taster of its advertising toolkit for advertisers in November at a time when marketers were trying to advertise for Friday Friday and Monday Monday.
Facebook did not reply to the CNBC request for comments immediately.
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