> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fiddler.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# StaleDatasetVersion

> Raised when a write names items that changed after the dataset version it was based on. Nothing was written. Reload the dataset, reconcile, and write again. `item_ids` holds the items the server names, and `server_message` the server's own wording.

**New in version 0.8.0**

## Example

```python theme={null}
from fiddler_evals import Dataset
from fiddler_evals.exceptions import StaleDatasetVersion

try:
    dataset.update_items(items=items)
except StaleDatasetVersion as e:
    print(f"Changed since v{dataset.version.version}: {e.item_ids}")
    dataset = Dataset.get_by_id(dataset.id)
```

## message

**Type:** `str`

**Value:** `'Items changed since the dataset version this write was based on'`

Human-readable error message; this class default is used when none is given.