Wednesday February 27, 2019


Trouble with unfurls, notifications and reminders

Issue Summary:

On February 27th at 09:43pm PST, we experienced some troubles with our default queue which may have caused some users to experience intermittent issues with link unfurls, notifications, and reminders within Slack. Our team identified the root cause of the problem, and at 12:40am PST on February 28th, normal functionality was restored.

4:09 PM PST

Unfurls, notifications and reminders are back to functioning at normal speeds. We're very sorry for the inconvenience and are working to ensure this doesn't happen again.

12:47 AM PST

We're starting to see improvements and expect the delays in unfurls, notifications and reminders to be decreasing as we speak. Thank you again for your patience and understanding.

12:23 AM PST

Our engineers are continuing to work on restoring normal functionality to these features. We really appreciate your patience!

11:58 PM PST

We're still exploring the cause of the issue affecting these features. We apologise for the trouble and appreciate you sticking with us.

11:28 PM PST

Nothing new to share on the issue with unfurls, notifications and reminders, but we're working on getting things back to normal as quickly as possible. Again, thank you for bearing with us.

10:58 PM PST

Our investigation of the unfurling issues are ongoing. Some people may see issues with notifications and reminders as well. We're terribly sorry for the disruption to your day.

10:28 PM PST

We've seen that unfurls may be running slow or failing. We’re looking into this as we speak.

9:58 PM PST

Services affected

Link Previews





Issues with Slack calls and slow loading pages

Issue Summary:

On February 27th at 6:04PM PST, we began experiencing some region-specific issues with our Content Delivery Network (CDN). During this period, some users may have experienced issues making calls, accessing the Admin or Checkout pages, installing and configuring apps or slower general performance. The issues with our CDN were addressed and by 10:08PM PST all functionality had returned to normal.

11:18 PM PST

We've fixed the issues with calls, and all pages should be loading fast once again. However, if you're still seeing issues with any of these features, please let us know at

10:41 PM PST

We've isolated the problem with calls and the slow loading pages. We’re working to bring these features back online for everyone. More details to come as they become available.

10:33 PM PST

We're still pinning down the cause for failing calls and certain pages loading slowly. We hope to bring some good news soon.

10:03 PM PST

We’re still working on fixing these features that have been impacting some workspaces. We really appreciate your patience.

9:34 PM PST

Our team are still looking into what’s causing these issues. In addition to calls, we've seen that other pages are affected and we'll continue to update you on our progress.

9:04 PM PST

We've received word that some people are having trouble starting calls, as well as accessing the Admin and Checkout pages. We're investigating and will be sharing constant updates. Sorry for the disruption to your day.

8:32 PM PST

Services affected



Workspace/Org Administration





Some folks are unable to view new custom emoji and profile photos.

Issue Summary:

At 10:09 AM PST on February 27th, we began experiencing intermittent issues with our Content Delivery Network (CDN). During this period, some users may have experienced problems loading custom emoji or profile images. Our CDN’s issues were resolved and full functionality was restored at 1:23 PM PST.

6:35 PM PST

We're happy to report that folks should be able to view new custom emoji and profile photos after a refresh. We're sorry for the trouble, and thanks for sticking with us.

3:15 PM PST

We've received word that some folks are unable to view new custom emoji and profile photos. We're looking into this, and we'll keep you posted on any updates.

1:16 PM PST

Services affected





Trouble editing posts

Issue Summary:

On February 27th 2019 between 4:45am and 6:36am PST, Slack experienced issues with Posts. In particular, an expired certificate for Slack's post servers prevented users from creating, modifying or reading Posts. We investigated the root cause and a valid certificate was generated and installed. We have made plans to prevent this from happening in the future.

6:34 PM PST

We're happy to report that the trouble with editing posts has now been resolved. We appreciate your patience and apologize for any inconvenience that was caused.

6:39 AM PST

Some customers are experiencing trouble typing in posts at this time. We apologise for any interruption and we will continue to investigate.

5:15 AM PST

Services affected