NOTICE DATE: September 11, 2026

NOTICE TYPE: M-C091126-01 Operations

SHORT DESCRIPTION: Unplanned System Outage

INTENDED AUDIENCE: All Market Participants

DAYS AFFECTED: September 9, 2026 09:11 - 14:28

LONG DESCRIPTION: ERCOT experienced an unexpected issue with ERCOT's Client Digital Certificate vendor that affected the functionality of the market facing Market Information System (MIS), External Web Services (EWS) Market Transactions, and other Digit Certificate secured websites.  Some Market Participants' certificate holders or Application Programming Interface (API) systems may have experienced issues connecting with the following services:   

• MIS.ERCOT.COM
• MISAPI.ERCOT.COM
• API.WAN.ERCOT.COM
• EWS GetReports and GetLists;
• Market Data Transparency (MDT) Web Services;
• Market submissions and requests via External Web Services (EWS);
• Market Manager;
• Outage Scheduler;
• Downloading of extracts and reports from the ERCOT MIS and ERCOT.com;
• Net Dependable Capability and Reactive Capability (NDCRC);
• Congestion Revenue Right (CRR) Market User Interface;
• MarkeTrak
• Find ESIID and Find Transaction;
• Market Participant Identity Manager (MPIM);
• Extract Subscriber;
• Service Requests
• Gateway.ercot.com
• MODWEB

ADDITIONAL INFORMATION: No reports or extracts missed posting.

CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at ClientServices@ercot.com.

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