That’s because messaging service Slack, which has more than 142,000 paying corporate customers including Fortune, was offline as of Monday morning—leaving knowledge workers returning to work after the New Year’s holiday with the loss of a critical software tool.

The company, which will be acquired by Salesforce for more than $27 billion, acknowledged the outage in a message at 10:14 a.m. ET. “Our team is investigating and we will follow up with more information as soon as we have it,” the message stated. “We apologize for any disruption.”

The outage comes as Slack is engaged a fierce battle for the corporate messaging market against Microsoft’s Teams and many other rivals. The company’s stock dropped sharply in September 2019 after it admitted paying $8 million in credits to customers hurt by outages in the second quarter of that year.

On Monday, Slack’s stock price lost 1% in morning trading. The stock gained over 90% in 2020.

The disruption also led to an outpouring of commentary on social media.

“I feel a great disturbance in the slack, as if millions of people tried to log on for the first time in two weeks and were suddenly silenced,” software analyst Steve O’Grady of RedMonk tweeted, referencing a famous line from Star Wars.

“Slack is broken, posts aren’t tweeting, and I cannot get enough coffee in me to wake up! Welcome to 2021!,” tweeted TechCrunch reporter Sarah Perez.

“It took me until today’s Slack outage to realize the name is a pun in that when the service is down you have a chance to slack off,” web designer and blogger Nate Hoffelder quipped on Twitter.