Cornerstone incident
Service Disruption: US SL4 – Login & 404 Error Issues
Cornerstone experienced a critical incident on January 30, 2026 affecting Uptime and Response Time, lasting 3h 9m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Jan 30, 2026, 03:11 PM UTC
US SL4 is currently experiencing a service disruption. Some users are unable to log in or are encountering 404 errors when accessing the application. This issue is our highest priority, and our team is actively working to resolve it as quickly as possible. We will provide further updates as soon they become available. Please check back periodically for the latest information.
- identified Jan 30, 2026, 04:29 PM UTC
The issue has been identified, and we are actively working on a fix to restore normal operations. We will share another update as we continue to make progress.
- monitoring Jan 30, 2026, 04:50 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved Jan 30, 2026, 06:20 PM UTC
After a period of monitoring and no recurrence, this is considered resolved.
- postmortem Feb 12, 2026, 08:59 PM UTC
**Issue Summary:** On January 30, 2026, clients hosted in the US SL4 Production environment experienced a temporary service disruption following scheduled maintenance activities. During the affected window, some users encountered intermittent access issues, resulting in brief periods of service unavailability. **Root Cause:** The incident was caused by a configuration inconsistency introduced during scheduled maintenance. Certain application components were not fully aligned, which interrupted an active service and led to temporary platform instability. **Corrective Action:** Upon identification, engineering teams promptly corrected the configuration misalignment and restored the affected components. The environment was stabilized and validated to confirm full restoration of service availability. **Preventive Measures:** To reduce the likelihood of recurrence, the following improvements were implemented: * Additional Maintenance Validation: Introduced additional automated validation checks during maintenance activities. * Configuration Safeguards: Strengthened safeguards to ensure configuration consistency across dependent services. * Improved Review Procedures: Enhanced maintenance review processes to minimize the risk of unintended service interruptions.