The popular office messaging app Slack suffered a major outage on February 26, 2025, which prevented thousands of users worldwide from communicating. Users started having trouble connecting to the platform, sending messages, and accessing channels at 10:30 a.m. Eastern Time. Over 3,000 users used DownDetector to report issues during its height. Users were unable to plan their workday or communicate with coworkers due to a disruption in the workplace messaging service. On Tuesday morning, thousands of Slack users worldwide and in Australia reported problems utilizing the workplace chat app.

A Salesforce representative informed Yahoo Finance that Slack’s functionality has now been fully restored. Users in Australia and around the world have been affected by the problem.

Duration and the Root Cause

The technical team at Slack determined that database shard failures, essential parts in charge of processing and allocating data requests, were the cause of the outage. A number of Slack functionality, including thread loading, workflows, and messaging, were impacted by these API failures. Over the day, services were progressively restored after the problem, which lasted for about ten hours.

Users complained of difficulties loading threads and connecting to Slack. According to the website DownDetector, over 6,000 users reported problems that peaked at around nine in the morning on Tuesday.

Slack stated,

“This was not affecting any specific region, but a percentage of users may have been affected globally,”.

Impact on Users in Australia

In Australia, Slack has around 277,000 daily active users, some of whom were affected by the outage. Businesses in Australia were greatly impacted by the outage, especially those in industries like technology and sales. Significantly impacted were sales teams, who mainly depend on Slack for real-time communication. Due to the delay in proposals and client communications, the disruption resulted in halted negotiations and hampered collaboration.

The event brought to light the dangers of depending just on one cloud-based communication platform. In order to lessen the effects of such disruptions in the future, organizations are increasingly thinking about putting in place backup communication lines and improving the resilience of their systems.

Many of Australia’s biggest businesses use the Salesforce-owned platform for project coordination and messaging. Still, it has been revealed that backend database routing issues have been the root cause of troubles impacting customers worldwide.

This indicates that the databases that hold all of the information and data saved in distinct channels and messages were not correctly talking with the company’s servers.

Users have been reporting about channels being unreachable and messages either not sending at all or sending inconsistently. Recently, the Slack company stated that its systems have been correctly restored, and users should soon notice that their services are operating normally again.

We implemented a modification, and Slack is showing indications of progress. In addition to client boots, users will see success with message sending, channel loading, threading, canvases, and Activity,” the business wrote.

“We sincerely regret any inconvenience caused to your day.”