RCA - Users cannot create experiments
Summary
Between at least 04:50 PM UTC and 09:35 PM UTC on Thursday, Dec 4, 2025, FME customers with more than 50 Feature flags in their project may have experienced issues creating Experiments from the UI. No data loss or any other issues were encountered.
Root Cause
An oversight in our testing coverage revealed that the Create Experiment form would fail if the user attempted to select a feature flag that was not in the first 50 results. This was a state issue that caused the UI component to not locate the correct feature flag, causing the form to silently fail. After identifying the issue, we deployed a fix to fully resolve the issue.
Impact
- Customers were possibly unable to create an Experiment if their project had more than 50 feature flags.
- All customers using Experiments in projects which had fewer than 50 feature flags were not impacted.
- Warehouse Native Experiments were not impacted by this issue.
Timeline
| Time (UTC) |
Event |
| 04:50 PM Dec 4, 2025 |
Customers reported issue with creating experiments. |
| 09:35 PMNov 17, 2025 |
Full restoration after fixing the UI component. |
Remediation
A code fix was deployed to fix the issue.
Action Items
- Fix the state issue in the component. The UI component should not be relying on a separate query to retrieve feature flags. It should be using the selected feature flag’s data instead.
- Improve testing coverage. For this particular component (and for other components that rely on paginated data), we should have proper integration testing in place to ensure that pagination does not break interactions like this.
- Additional metrics and alerting. There were no logs or alerts on this issue. Debugging was very challenging and it wasn’t clear where the error was coming from. We should make sure that we have proper logging and alerts in place to catch these issues sooner.