Your config.json contains an illegal accessory configuration

Error message

Your config.json contains an illegal accessory configuration object at position %d. Missing property 'accessory'. Skipping entry...

What it means

Homebridge validates every entry in config.json's accessories[] array at startup. Each entry must have an 'accessory' property naming which registered accessory plugin to instantiate. When the property is missing, loadAccessories logs this warning and skips the entry instead of crashing the bridge.

Source

Thrown at src/server.ts:458

        MDNSAdvertiser.AVAHI,
        MDNSAdvertiser.RESOLVED,
      ].includes(config.bridge.advertiser)) {
        config.bridge.advertiser = undefined
        log.error('Value provided in bridge.advertiser is not valid, reverting to platform default.')
      }
    } else {
      config.bridge.advertiser = undefined
    }

    return config as HomebridgeConfig
  }

  private loadAccessories(): void {
    log.info(`Loading ${this.config.accessories.length} accessories...`)

    this.config.accessories.forEach((accessoryConfig, index) => {
      if (!accessoryConfig.accessory) {
        log.warn('Your config.json contains an illegal accessory configuration object at position %d. '
          + 'Missing property \'accessory\'. Skipping entry...', index + 1) // we rather count from 1 for the normal people?
        return
      }

      const accessoryIdentifier: AccessoryName | AccessoryIdentifier = accessoryConfig.accessory
      const displayName = accessoryConfig.name
      if (!displayName) {
        log.warn('Could not load accessory %s at position %d as it is missing the required \'name\' property!', accessoryIdentifier, index + 1)
        return
      }

      let plugin: Plugin
      let constructor: AccessoryPluginConstructor

      try {
        plugin = this.pluginManager.getPluginForAccessory(accessoryIdentifier)
      } catch (error: any) {
        log.error(error.message)

View on GitHub (pinned to edf5493034)

Solutions

Open config.json and add the 'accessory' property with the exact accessory identifier the plugin registered
Remove the empty/invalid object from the accessories array if it is a leftover placeholder
Validate config.json with a JSON linter and compare against the plugin's documented config schema.example

Example fix

// before
"accessories": [
  { "name": "Lamp" }
]
// after
"accessories": [
  { "accessory": "DomoticaLamp", "name": "Lamp" }
]

Defensive patterns

Strategy: validation

Validate before calling

const missing = config.accessories?.filter(a => !a || typeof a !== 'object' || !a.accessory) ?? []
if (missing.length) throw new Error(`Accessory entries missing 'accessory' property: ${missing.length}`)

Type guard

function isValidAccessoryConfig(c: unknown): c is { accessory: string; name: string; [k: string]: unknown } {
  return typeof c === 'object' && c !== null && typeof (c as any).accessory === 'string' && (c as any).accessory.length > 0
}

Prevention

Use Homebridge config.schema.json validation (config-ui-x does this automatically)
Never hand-edit config.json without running it through a JSON validator
Keep the 'accessory' key copied verbatim from plugin documentation

When it happens

Trigger: An object in config.json under 'accessories' has no 'accessory' key (e.g. only 'name', or a malformed/renamed key like 'accessoryName').

Common situations: Hand-edited config with a typo, a config editor writing an empty placeholder object, copy-pasting a platform block into accessories, or trailing incomplete entry after a truncated edit.

Related errors

AI-assisted analysis of homebridge/homebridge@edf5493034 (2026-08-30). Data as JSON: /api/errors/e7e3f8b73e707130. Report an issue: GitHub.