Facebook, Instagram and WhatsApp services started coming online on Tuesday morning Indian time, around five to six hours after users in several parts of the world started experiencing problems accessing the applications. Facebook blamed the outage on a “faulty configuration change”.

“Our engineering teams have learned that configuration changes on the backbone routers that coordinate network traffic between our data centers caused issues that interrupted this communication,” the company said in a blog. “This disruption to network traffic had a cascading effect on the way our data centers communicate, bringing our services to a halt.”

The error message on Facebook’s webpage had indicated that the outage was due to an problem in the Domain Name System, which enable web addresses to take users to their destinations.

The services began reconnecting around 3.30 am on Tuesday (Indian Standard Time), reported Reuters.

Downdetector, a portal that detects outages on websites, showed that at 9.38 pm on Monday, there were more than 6,900 reports of outages on Facebook. For WhatsApp, there were nearly 30,000 such reports at the same time period. At of 9.27 pm, 18,739 Instagram outages had been reported.

Soon after the outage began, Facebook had acknowledged that users were having trouble accessing its applications but did not provide any specifics details about the nature of the problem.

In its blog, Facebook, which also owns Instagram and WhatsApp, acknowledged that such outages impact people’s lives and that the company was responsible for informing them about such disruptions.

“We apologize to all those affected, and we’re working to understand more about what happened today so we can continue to make our infrastructure more resilient,” it said.

The social media giant also said that there was no evidence to show that any user data was compromised as a result of this downtime. The clarification came after media reports suggested that data of over 150 crore Facebook users were allegedly being sold on the dark web.

However, online cybersecurity portal Privacy Affairs, which was on the first to report on the matter, clarified that the alleged sale of data was not related to the outage as it had published the article 12 hours before Facebook services went down.

After services began reconnecting, Facebook Chief Technology Officer Mike Schroepfer tweeted that that the app might take some time to be restored to 100% functioning.

“The global Facebook outage is now one of the largest ever tracked on Downdetector in terms of the total number of reports [over 1.4 crore as of 3.30 am Indian Standard Time] and duration; this is an extremely impactful event,” said Luke Deryckx, chief technical officer of Ookla, a company that evaluates internet access performance metrics.

Meanwhile, Facebook shares fell 5.3% on Monday, the biggest that company has seen since November. The company’s stocks rose around 0.5% after trading hours as the services began reconnecting.

The social media giant was losing about $5,45,000, or approximately Rs 4 crore, in the United States every hour in advertisement revenues, Reuters reported, citing estimates of an ad measurement company Standard Media Index.

Zuckerberg loses over $6 billion

Meanwhile, Facebook founder and Chief Executive Officer Mark Zuckerberg lost over $6 billion, or more than Rs 44.75 thousand crore, in a few hours amid the outage and allegations levelled by a whistleblower, reported Bloomberg.

Zuckerberg’s net worth slumped to $121.6 billion, or over Rs 9.06 lakh crore, pushing him to the fifth position in the Bloomberg Billionaire Index.

Facebook is also plagued by a series of articles published in Wall Street Journal reportedly based on internal company documents that claimed the social media giant knew about various problems with the application but downplayed them in public.

These problems included Instagram’s harm to the mental health of teenage girls and misinformation about the January 6 Capitol riots in the United States.

The whistleblower, Frances Haugen is a former Facebook employee. He will be testifying against the company in the US Congress on Tuesday.