> For the complete documentation index, see [llms.txt](https://docs.mapbox.com/mapbox-tiling-service/ja/llms.txt)

# Warnings

Even a successful [Mapbox Tiling Service](https://docs.mapbox.com/api/maps/mapbox-tiling-service/) (MTS) job may have some warnings, indicating that some features in your tileset source(s) were dropped in the resulting [tileset](https://docs.mapbox.com/help/glossary/tileset/). Each warning contains information about how to make sure the feature is not dropped in your next job.

## Types of warnings

| Code | Description | Example |
| --- | --- | --- |
| `W201` | One or more features were dropped due to [tile size limits](https://docs.mapbox.com/mapbox-tiling-service/ja/guides/warnings/#tile-size-limits). | W201: Features were dropped from mountains layer in 2 tile(s) to enforce tile size limits. Affected zoom levels are: 0,2. Affected tiles and their required layer_sizes include: `{"layer_size":4433,"tile":"0/0/0"}, {"layer_size":1154,"tile":"2/0/1"}`. |
| `W202` | One or more features were dropped due to [decoding errors](https://docs.mapbox.com/mapbox-tiling-service/ja/guides/warnings/#geojson-encoding). | W202: LineString must contain at least 2 points - Example: `{"id":5,"type":"Feature","properties":{},"geometry":{"type":"LineString","coordinates":[]}}` |
| `W203` | One or more features were dropped due to [encoding errors](https://docs.mapbox.com/mapbox-tiling-service/ja/guides/warnings/#geojson-encoding). | W203: Invalid number of points in polygon ring, can not encode - Example: `{"id":18,"type":"Feature","properties":{},"geometry":{"type":"Polygon","coordinates":[[[100.0,0.0],[101.0,0.0]]]}}` |
| `W204` | One or more features were dropped due to duplicate ids; make sure every feature in your tileset source has a unique id to avoid this warning. | W204: Feature(s) were dropped from restaurants layer because of duplicate feature ids. Affected feature ids include: 724305,4196773 |
| `W205` | One or more layers were dropped due to their filters returning no bands from the tileset sources. | W205: Layer 'temperature' was dropped from the tileset because its filter found no associated bands. |

Note: `W202` and `W203` errors are capped to `20` per job, and may not include all the decoding/encoding errors in your source data.

## Troubleshooting

### Tile Size Limits

MTS Tilesets are normally capped at 1250 KB per layer. If a layer exceeds that size, the Mapbox Tiling Service will drop features and emit a `W201` warning. Every `W201` warning contains the layer and zoom level(s) where the features were dropped, as well as a list of specific tiles that were too large, each with the `layer_size` that would have been [required in the recipe](https://docs.mapbox.com/mapbox-tiling-service/ja/recipe-specification/vector/#layer-size) to prevent that tile from being capped. Recommendations for how to avoid this warning vary according to your data and use case; for more information, read our documentation on what to do if you see gaps of [missing data in your tiles](https://docs.mapbox.com/mapbox-tiling-service/ja/guides/frequentlyaskedquestions/#there-are-gaps-of-missing-data-in-my-tiles).

Once you have made the recommended changes, you will need to re-publish the tileset to see the feature(s) in the updated tileset.

### GeoJSON Encoding

If there are incorrectly formatted GeoJSON features in your [tileset source](https://docs.mapbox.com/help/glossary/tileset-source/), the Mapbox Tiling Service will drop the feature and emit a `W202` or `W203` warning. Every `W202` or `W203` warning contains an example of the dropped feature, to help you identify the formatting bug.

Because tileset sources can be large, `W202` and `W203` errors are capped to `20` per job, and may not include all the decoding/encoding errors in your source data. To track down all the GeoJSON errors in your dataset, we recommend using the tilesets CLI to [validate your tileset source(s)](https://docs.mapbox.com/mapbox-tiling-service/ja/vector/supported-file-formats#validate-line-delimited-geojson). Once you have identified and fixed the issue, you will need to re-upload your source data and re-publish the tileset to see the feature(s) in the updated tileset.