Node-RED Web UI loads only partially

I installed a node red instance on my rpi today. I did it with docker.

      nodered:
          container_name: nodered
          restart: always
          image: 'nodered/node-red-docker:rpi-v8'
          ports:
              - "8083:1880"
         volumes:
             - "/media/data/volumes/nodered:/data"
         networks:
             - js

The log outputs are also very inconspicuous:

npm info it worked if it ends with ok
npm info using npm@3.10.10
npm info using node@v6.11.0
npm info lifecycle node-red-docker@1.0.0~prestart: node-red-docker@1.0.0
npm info lifecycle node-red-docker@1.0.0~start: node-red-docker@1.0.0

node-red-docker@1.0.0 start /usr/src/node-red
node $NODE_OPTIONS node_modules/node-red/red.js -v $FLOWS "--userDir" "/data"

31 Jul 23:27:24 - [info]

Welcome to Node-RED

31 Jul 23:27:24 - [info] Node-RED version: v0.17.5
31 Jul 23:27:24 - [info] Node.js version: v6.11.0
31 Jul 23:27:24 - [info] Linux 4.14.56-v7+ arm LE
31 Jul 23:27:25 - [info] Loading palette nodes
31 Jul 23:27:29 - [warn] Missing node modules:
31 Jul 23:27:29 - [warn] - node-red (0.17.5): sort, batch
31 Jul 23:27:29 - [info] Removing modules from config
31 Jul 23:27:29 - [info] Settings file : /data/settings.js
31 Jul 23:27:29 - [info] User directory : /data
31 Jul 23:27:29 - [info] Flows file : /data/flows.json
31 Jul 23:27:29 - [info] Creating new flow file
31 Jul 23:27:29 - [info] Starting flows
31 Jul 23:27:29 - [info] Started flows
31 Jul 23:27:30 - [info] Server now running at http://127.0.0.1:1880/

However, I have a problem calling the Web UI. The UI loads only partially. The missing data is not transmitted to the browser. I tried different node red versions and browsers. It's always the same: