Can’t open Word/Excel files in OnlyOffice

I’m running Seafile 11.0.13 in a Docker container on a VPS. I’m not using a reverse proxy; I’m just trying to get this working via http:// vps.ip:port (and once it is, I’ll setup a public hostname on a Cloudflare tunnel).

When I login to Seafile, open “My Library” and create any sort of Word/Excel/etc. file, I get this message:

Warning

Can’t save this doc. Check your connection settings or contact your admin.
When you click the ‘OK’ button, you will be prompted to download the document.

I’ve tried searching for similar issues but everyone seems to be running Seafile via https/behind a reverse proxy. I tried following the Official setup procedure (at manual.seafile dot com /docker/deploy_seafile_with_docker)
And the unofficial/recommended setup (at datamate-rethink-it.github dot io)
Both of those gave me an SSL error; I couldn’t even get to the Seafile login page.

Nothing works for me but the docker-compose.yml below comes very close. Seafile loads as expected and I can login. If I change the port to access OnlyOffice, I get the Welcome page. And if I run the docker exec command to “Test Before Integration”, everything works properly. But going back to Seafile and trying to create a Word or Excel doc, I get the aforementioned error.

When I try to upload a document, I get this error:

The Seafile log is error free, but the OnlyOffice log shows errors (which I can’t post because it contains links)

My docker-compose.yml :

services:
  mysql:
    image: mariadb:10.11
    container_name: ${MYSQL_CONTAINER_NAME}
    environment:
      - MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PASSWORD}
      - MYSQL_DATABASE=${MYSQL_DATABASE}
      - MYSQL_USER=${MYSQL_USER}
      - MYSQL_PASSWORD=${MYSQL_PASSWORD}
      - TZ=${TZ}
    volumes:
      - ${MYSQL_DATA}:/var/lib/mysql
    networks:
      - seafile-net
    restart: unless-stopped

  seafile:
    image: seafileltd/seafile-mc:latest
    container_name: ${SEAFILE_CONTAINER_NAME}
    ports:
      - "${SEAFILE_PORT}:80"
    volumes:
      - ${SEAFILE_DATA}:/shared
    environment:
      - DB_HOST=mysql
      - DB_ROOT_PASSWD=${MYSQL_ROOT_PASSWORD}
      - DB_USER=${MYSQL_USER}
      - DB_USER_PASSWD=${MYSQL_PASSWORD}
      - SEAFILE_ADMIN_EMAIL=${SEAFILE_ADMIN_EMAIL}
      - SEAFILE_ADMIN_PASSWORD=${SEAFILE_ADMIN_PASSWORD}
      - SEAFILE_SERVER_HOSTNAME=${SEAFILE_SERVER_HOSTNAME}
      - SEAFILE_SERVER_LETSENCRYPT=${SEAFILE_SERVER_LETSENCRYPT}
      - TZ=${TZ}
    depends_on:
      - mysql
    networks:
      - seafile-net
    restart: unless-stopped

  onlyoffice:
    image: onlyoffice/documentserver:latest
    container_name: ${ONLYOFFICE_CONTAINER_NAME}
    ports:
      - "${ONLYOFFICE_PORT}:80"
    volumes:
      - ${ONLYOFFICE_DATA}:/var/www/onlyoffice/Data
    environment:
      - JWT_ENABLED=true
      - JWT_SECRET=${ONLYOFFICE_JWT_SECRET}
      - TZ=${TZ}
    networks:
      - seafile-net
    restart: unless-stopped

networks:
  seafile-net:
    driver: bridge

I seem to have gotten it working - sort of… I can now upload documents and create new ones. But when I try to open a Word.docx file, I get an error saying “Can’t save this doc. Check your connection settings or contact the admin. When you click OK, you will be prompted to download the document.” - but then the document displays behind the error dialog. When I click “OK”, the message changes to “Warning
Using the free Community version, you can open documents for viewing only. To access mobile web editors, a commercial license is required.” I’m not sure if this is a message from Seafile or OnlyOffice. If it’s a Seafile limitation, I know the Professional Edition of Seafile is free for up to 3 users. (I only have 2.) Is there a simple way to upgrade?

I don’t think a pro license is required to make editing files work. I use collabora with seafile to edit word files, spreadsheets, etc.