What Luna Studio checks
Schema checks
- The file parses as CSV or JSONL.
- Required columns are present:
- Test sets — metric-specific feature columns and
label. - Training sets — metric-specific feature columns and optionally
labelwhen applicable.
- Test sets — metric-specific feature columns and
- Column types match the metric’s output type (e.g. labels are parseable as Boolean for a Boolean metric).
Content checks
- File encoding (UTF-8 expected).
- Row count > 0.
- Empty rows or empty cells
File checks (uploads and URLs)
- File size within the upload limit.
- For URLs: the URL is reachable; the response content type is appropriate.
Common errors
| Error message | Cause | Fix |
|---|---|---|
Missing column "label" in uploaded CSV. | Test set or labelled training set without a label column. | Add the column to your file and re-upload. For unlabelled training logs, use the label-only flow from Step 3. |
Missing column "input" in uploaded CSV. | Required input column missing. | Rename your input column to input, or include one. |
Could not fetch URL. | The URL was unreachable, returned a non-2xx status, or required auth. | Check the URL is correct; for cloud URLs, confirm the relevant integration has access. |
Unsupported file type. | The file isn’t .csv or .jsonl. | Convert the file to one of the supported formats. |
Empty dataset. | The file parsed but had zero data rows. | Confirm the file isn’t header-only. |
Label values don't match metric output type. | Labels can’t be parsed as the metric’s expected type. | Re-check labels (e.g. for Boolean: only true/false or 1/0). |
Where to go next
Add a dataset
Walk through the three sources.
Troubleshooting
Run-time failures and how to recover.