Bonjour Norbert,
Merci pour votre retour. Je viens d’essayer en supprimant le plugin, ainsi que mosquitto et le répertoire /opt/zigbee2mqtt, un redémarrage, puis ré-installation du plugin, installation des dépendances et renseignement de l’adaptateur & port : idem 
(hormis quelques lignes de plus dans les logs):
> zigbee2mqtt@1.30.4 start
> node index.js
Zigbee2MQTT:debug 2023-05-15 10:20:15: Loaded state from file /var/www/html/plugins/zigbee2mqtt/data/zigbee2mqtt/state.json
Zigbee2MQTT:info 2023-05-15 10:20:15: Logging to console and directory: '/var/www/html/plugins/zigbee2mqtt/data/zigbee2mqtt/log/2023-05-15.10-20-15' filename: log.txt
Zigbee2MQTT:info 2023-05-15 10:20:15: Starting Zigbee2MQTT version 1.30.4 (commit #daedc54d)
Zigbee2MQTT:info 2023-05-15 10:20:15: Starting zigbee-herdsman (0.14.111)
Zigbee2MQTT:debug 2023-05-15 10:20:15: Using zigbee-herdsman with settings: '{"adapter":{"concurrent":null,"delay":null,"disableLED":false},"backupPath":"/var/www/html/plugins/zigbee2mqtt/data/zigbee2mqtt/coordinator_backup.json","databaseBackupPath":"/var/www/html/plugins/zigbee2mqtt/data/zigbee2mqtt/database.db.backup","databasePath":"/var/www/html/plugins/zigbee2mqtt/data/zigbee2mqtt/database.db","network":{"channelList":[20],"extendedPanID":[221,221,221,221,221,221,221,221],"networkKey":"HIDDEN","panID":52611},"serialPort":{"adapter":"deconz","path":"/dev/ttyACM0"}}'
2023-05-15T08:20:16.062Z zigbee-herdsman:controller:device:log Request Queue (0x00212effff085cc3): default expiration timeout set to 0
Zigbee2MQTT:debug 2023-05-15 10:20:16: Saving state to file /var/www/html/plugins/zigbee2mqtt/data/zigbee2mqtt/state.json
Zigbee2MQTT:error 2023-05-15 10:20:16: Not connected to MQTT server!
Zigbee2MQTT:error 2023-05-15 10:20:16: Cannot send message: topic: 'zigbee2mqtt/bridge/state', payload: 'offline
Zigbee2MQTT:info 2023-05-15 10:20:16: Disconnecting from MQTT server
/opt/zigbee2mqtt/lib/mqtt.ts:129
this.client.end();
^
TypeError: Cannot read properties of undefined (reading 'end')
at MQTT.disconnect (/opt/zigbee2mqtt/lib/mqtt.ts:129:21)
at Controller.stop (/opt/zigbee2mqtt/lib/controller.ts:198:9)
at stop (/opt/zigbee2mqtt/index.js:111:5)
at process.handleQuit (/opt/zigbee2mqtt/index.js:117:9)
Après une deuxième installation des dépendances, je reviens sur les logs initiaux:
> zigbee2mqtt@1.30.4 start
> node index.js
Building Zigbee2MQTT... (initial build), failed
Error: Command failed: npm run build
at ChildProcess.exithandler (node:child_process:402:12)
at ChildProcess.emit (node:events:513:28)
at maybeClose (node:internal/child_process:1100:16)
at Process.ChildProcess._handle.onexit (node:internal/child_process:304:5)