User impact: Users may be intermittently unable to download attachments or view embedded images in Outlook on the web.

More info: To ensure our mitigation takes effect, users will need to logout and log back into their Outlook on the web accounts. This issue may impact those who are downloading attachments or viewing embedded images in Outlook on the web.

Users may see the following error message when an attachment fails to download: “Error downloading the file content.” Downloading attachments and embedded image viewing may succeed after signing out and then back into Outlook on the web. If available, users can download attachments and view embedded images consistently through the Outlook desktop client or the Outlook mobile app.

Current status: We have verified the scope of impact for this event and our communications have been updated to ensure all of our affected tenants are informed of this issue. In parallel, our deployment of the fix is still ongoing and we expect that users will see relief as it reaches their environment.

Scope of impact: Users attempting to download attachments and viewing embedded images in Outlook on the web or Outlook mobile apps may be intermittently impacted.

Start time: Friday, March 29, 2024, at 12:00 AM UTC

Root cause: A recent update, intended to improve the reliability of Outlook on the web and Outlook mobile apps, contains a code configuration issue that’s causing long running sessions, preventing attachment downloads and embedded image viewing.

Next update by: Monday, April 15, 2024, at 11:00 PM UTC