# [costmap_2d] Unknown layer type specified: 'inflation_layer' in plugin list

- **ID:** `ros2/nav2-costmap-inflator-unknown-layer`
- **Domain:** ros2
- **Category:** config_error
- **Verification:** ai_generated
- **Fix Rate:** 90%

## Root Cause

The costmap configuration YAML file lists 'inflation_layer' as a plugin, but the plugin name is misspelled or the plugin is not registered in the costmap's plugin list.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| Nav2 (Humble, Iron, Rolling) | active | — | — |
| costmap_2d plugin version 2.0.0+ | active | — | — |

## Workarounds

1. **Correct the layer name in the YAML file: change 'inflation_layer' to 'inflation_layer' (note: the correct name is 'inflation_layer', not 'inflation'). Also ensure the plugin list includes: plugins: ['obstacle_layer', 'inflation_layer', 'static_layer']** (95% success)
   ```
   Correct the layer name in the YAML file: change 'inflation_layer' to 'inflation_layer' (note: the correct name is 'inflation_layer', not 'inflation'). Also ensure the plugin list includes: plugins: ['obstacle_layer', 'inflation_layer', 'static_layer']
   ```
2. **If using a custom layer, register it with pluginlib and add it to the costmap's plugin list in the YAML.** (80% success)
   ```
   If using a custom layer, register it with pluginlib and add it to the costmap's plugin list in the YAML.
   ```

## Dead Ends

- **Reinstall nav2_costmap_2d package** — The plugin is included by default; the issue is a configuration typo, not a missing package. (70% fail)
- **Add the layer to the plugins list with a different name** — The plugin name must exactly match the registered class name 'inflation_layer'. (90% fail)