Slack experienced a major incident on December 4, 2025 affecting Canvases, lasting 18m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- resolved Dec 04, 2025, 11:43 PM UTC
Between 2:08 PM PST and 2:34 PM PST on December 4, 2025, some users may have experienced 500 errors when trying to open a Canvas. Current status and recent actions taken: We have resolved the issue by reverting a web cache configuration setting that was causing the disruption. Users should no longer be experiencing trouble connecting to or loading Canvases in Slack.Scope: This issue did not affect any specific region, but a percentage of users may have been impacted globally.Previous impact to end users: Users experienced issues loading and accessing Canvases.Required resolution steps: NoneThis issue is now resolved for all users. We’re sorry for the disruption we brought to your day.