Cornerstone experienced a major incident on August 20, 2026 affecting Response Time and Response Time and 1 more component, lasting 45m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- identified Aug 20, 2026, 12:06 PM UTC
Error when creating vILT session (Microsoft Teams VILT Integration): "Error while creating Schedule: Exception of type 'System.ArgumentException' was thrown." Cause has been found and we are working on the fix.
- resolved Aug 20, 2026, 12:51 PM UTC
This incident has been resolved.
- postmortem Aug 20, 2026, 01:51 PM UTC
This issue has resurfaced. The engineering team is working towards solution.
- postmortem Sep 01, 2026, 06:47 AM UTC
**Root Cause Analysis** **Incident Summary:** On August 20th, 2026, users in the UK Production and Pilot environments, across all swimlanes, experienced issues creating VILT sessions. **Impact:** Users were unable to create VILT sessions, resulting in temporary disruption to VILT-related functionality. **Root Cause:** The issue was related to the availability of the required messaging queues used by the VILT integration service. The queues were not available as expected, resulting in exceptions and preventing the service from processing VILT requests successfully. **Resolution:** The VILT integration service was redeployed in the UK Production and Pilot environments. Following the redeployment, the required queues were successfully established and the exceptions stopped. VILT session creation functionality was restored. **Preventive Measures:** * Queue availability and service startup dependencies are being reviewed to ensure the required queues are available during service initialization * Startup and redeployment sequencing are being reviewed to prevent similar queue initialization issues in the future