Node Red Add-on no longer starts

Node Red was working well. I just added an Alexa node to a flow and now the Add-on no longer starts. This is the log below:

hassio-addon-node-red@ start /opt
node $NODE_OPTIONS node_modules/node-red/red.js “–settings” “/etc/node-red/config.js”

15 Jan 20:48:13 - [info]

Welcome to Node-RED

15 Jan 20:48:13 - [info] Node-RED version: v0.19.5
15 Jan 20:48:13 - [info] Node.js version: v8.14.0
15 Jan 20:48:13 - [info] Linux 4.15.0-43-generic x64 LE
15 Jan 20:48:14 - [info] Loading palette nodes
15 Jan 20:48:14 - [warn] rpi-gpio : Raspberry Pi specific node set inactive
15 Jan 20:48:15 - [info] Dashboard version 2.13.0 started at /ui
15 Jan 20:48:15 - [warn] ------------------------------------------------------
15 Jan 20:48:15 - [warn] [node-red-contrib-alexa-home-skill/alexa] Type already registered
15 Jan 20:48:15 - [warn] ------------------------------------------------------
15 Jan 20:48:15 - [info] Settings file : /etc/node-red/config.js
15 Jan 20:48:15 - [info] Context store : ‘default’ [module=memory]
15 Jan 20:48:15 - [info] User directory : /config/node-red/
15 Jan 20:48:15 - [warn] Projects disabled : editorTheme.projects.enabled=false
15 Jan 20:48:15 - [info] Flows file : /config/node-red/flows.json
15 Jan 20:48:15 - [info] Server now running at https://127.0.0.1:1880/
15 Jan 20:48:15 - [info] Starting flows
15 Jan 20:48:15 - [info] Started flows
15 Jan 20:48:15 - [red] Uncaught Exception:
15 Jan 20:48:15 - Error: bind EADDRINUSE 0.0.0.0:1900
at _handle.lookup (dgram.js:266:18)
at _combinedTickCallback (internal/process/next_tick.js:142:11)
at process._tickCallback (internal/process/next_tick.js:181:9)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! hassio-addon-node-red@ start: node $NODE_OPTIONS node_modules/node-red/red.js "--settings" "/etc/node-red/config.js"
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the hassio-addon-node-red@ start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR! /root/.npm/_logs/2019-01-16T01_48_16_006Z-debug.log

Same error for me. Any clue?