By Dhirendra Tripathi

Investing.com – Facebook stock (NASDAQ:) traded 1.6% higher in premarket a day after a six-hour global outage shuttered all the apps under its umbrella and took the share nearly 5% lower at close.

The disruption, the worst in the company’s history, kept billions of users out of the parent app, Whatsapp, Instagram and Facebook messenger. Zuckerberg later apologised for the disruption.

While Facebook’s operations have been improving since the outbreak, it has also faced increasing headwinds over the past few weeks. Due to publicity surrounding the allegations made by a whistleblower against Facebook, which provided the basis to several Wall Street Journal articles at the weekend and CBS’s 60 Minutes on the weekend, the stock was already down 3% Monday prior to the outage. Frances Haugen will make the same allegations to Congress on Tuesday.

Politico also reported that shareholders filed suit against Zuckerberg late September. They claim that Zuckerberg overpaid the Federal Trade Commission a fine to protect Mark Zuckerberg, the CEO, from personal liability.

According to the social media company, the cause of the disruption was a configuration error on backbone routers which coordinate traffic between data centers. The disruption to network traffic had a cascading effect on the way its data centers communicate, bringing the services to a halt, Santosh Janardhan, Facebook’s vice-president, infrastructure, said in a blog post.

The breakdown wasn’t limited to the world outside. It also affected many of the systems and tools the company relies on in daily operations. Janardhan explained that it was difficult for the engineers to fix and diagnose the problem.

The company has not confirmed reports of malicious hacking that circulated Monday.