# Sigma Computing: Major incident: Workbooks not loading for Sigma users on AWS Snowflake

**Summary:** Sigma Computing reported a major outage causing workbooks not to load and queries to hang for AWS US and AWS EU users using Snowflake CDW. The final update corrected the start to approximately 2023-09-14 12:49 UTC; mitigation resolved it at 2023-09-14 17:24 UTC (computed duration: 2 h 43 min). _(machine-written, sol)_
- Kind: Major incident · Label: outage (model (Jev))
- Changed: 2023-09-14 14:41 UTC · Detected: 2026-10-17 18:22 UTC
- [Source: https://stspg.io/t0wp1hgjnpmj](https://stspg.io/t0wp1hgjnpmj)
- [Company: Sigma Computing](https://rewindex.com/company/sigma-computing.md)
- Versions: before (none: first archived) → after incident\_version:77/czgbhs4hyh1j@3ba663f6c024
- Change 1 of 1 for this incident

## What changed

**1. Added: Title**

```diff
+ Workbooks not loading for Sigma users on AWS Snowflake
```

**2. Added: Impact**

```diff
+ major
```

**3. Added: Status**

```diff
+ postmortem
```

**4. Added: Start time**

```diff
+ 2023-09-14 14:41 UTC
```

**5. Added: Resolved time**

```diff
+ 2023-09-14 17:24 UTC
```

**6. Added: Affected components**

```diff
+ AWS - Sigma - AWS (Canada), AWS - Sigma - AWS (Europe), AWS - Sigma - AWS (US), Azure - Sigma - Azure (US), GCP - Sigma - GCP (US), Sigma - AWS (Europe), Sigma - AWS (US)
```

**7. Added: Update** (investigating) · 2023-09-14 14:41 UTC

```diff
+ We are investigating an issue with workbooks not loading and queries hanging. We are treating this as our highest priority. Our apologies for any inconvenience caused. Impacted Cloud Regions & Services: Sigma users hosted on AWS US & AWS EU using Snowflake CDW Incident Start Time: Approximately 14:12 UTC September 14, 2023
```

**8. Added: Update** (investigating) · 2023-09-14 15:15 UTC

```diff
+ We are continuing to investigate this issue.
```

**9. Added: Update** (monitoring) · 2023-09-14 15:27 UTC

```diff
+ Our engineers have implemented mitigation measures and we are monitoring the effect closely. Impacted Cloud Regions & Services: Sigma users hosted on AWS US & AWS EU using Snowflake CDW User Experience: We expected workbooks to load normally starting 14:48 UTC for AWS US users and at 15:01 UTC for AWS EU users.  Incident Start Time: Approximately 14:12 UTC Sep 14, 2023 Note: A correction was made for the incident start time to be in 24-Hour time
```

**10. Added: Update** (resolved) · 2023-09-14 17:24 UTC

```diff
+ The mitigation measures have proven effective, and the issue is resolved. We will perform a root cause analysis (RCA) and publish our findings in a postmortem note to the Sigma Community site in coming days. You will receive a notification when that occurs. Impacted Cloud Regions & Services: Sigma users hosted on AWS US & AWS EU using Snowflake CDW Incident Start Time: Approximately 12:49 UTC September 14, 2023 Incident End Time: Approximately 14:39 UTC September 14, 2023
```

**11. Added: Update** (postmortem) · 2023-09-29 18:31 UTC

```diff
+ Sigma Engineering has completed the postmortem of this incident. A Root Cause Analysis \(RCA\) is available on the Sigma Community site: [Postmortem for September 14th, 2023; Workbooks not loading for Sigma users on AWS Snowflake](https://community.sigmacomputing.com/t/post-mortem-for-september-14th-2023-workbooks-not-loading-for-sigma-users-on-aws-snowflake/2604)
```

## History of this incident

| When (UTC) | Change | Label |
| --- | --- | --- |
| 2023-09-14 14:41 UTC | Major incident: Workbooks not loading for Sigma users on AWS Snowflake (this change) | outage |

All Sigma Computing changes: [timeline](https://rewindex.com/company/sigma-computing/changes.md)
_Diff excerpts are shown on normalized text: dates, counters and tokens appear as ‹date›, ‹count›, ‹tok›; noise-only edits are hidden. Rewindex shows the changed passages, not a copy of the page._


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Canonical: https://rewindex.com/change/i0b8caf6785a7e7 · Markdown: https://rewindex.com/change/i0b8caf6785a7e7.md · JSON: https://rewindex.com/api/v1/changes/i0b8caf6785a7e7 · Generated 2026-10-18T03:32:19.582Z