Final Status: Engineers determined the root cause, and deployed a fix to the affected environment, which has remediated impact.
User Experience: Affected users on an external network were unable to preview or download files. The issue persisted if the user then switched back to their internal network.
Customer Impact: Analysis of incident scope indicated that many customers appeared to be impacted by this event. For those customers affected, this issue potentially affected any user attempting to preview or download files. Engineers received a few isolated customer reports of this issue.
Incident Start Time: Tuesday, October 20, 2015, at 1:15 PM UTC
Incident End Time: Friday, October 23, 2015, at 12:59 AM UTC
Preliminary Root Cause: As part of our efforts to improve user experiences, an update was deployed to the infrastructure; however, the update caused a network token authentication issue.
Next Steps: The following is a list of known action item(s) associated with this incident. As part of the Office 365 problem management process, additional engineering actions may be identified to improve the overall service.
– Action: Review procedures for validating service updates, as the token authentication issue was not identified during the testing phase of the development process.
Please consider this service notification the final update on the event.