[BUG] Firefox extension: Login failed: NetworkError when attempting to fetch resource.

[Chaz6]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

When attempting to configure the Firefox extension, I loaded admin.json into the extension successfully, but when I try to Login & Test it shows Login failed: NetworkError when attempting to fetch resource..

The log from the server shows:-

sealskin  | [2026-01-23 10:40:55] [WARNING] [uvicorn.error] Invalid HTTP request received.

Expected Behavior

No response

Steps To Reproduce

Using the example docker-compose.yml to run the server, and Firefox as the client.

Environment

- OS: Fedora 43
- How docker service was installed: Docker CE from `https://download.docker.com/linux/fedora/$releasever/$basearch/stable`

CPU architecture

x86-64

Docker creation

cat >docker-compose.yml <<EOF
---
services:
  sealskin:
    image: lscr.io/linuxserver/sealskin:latest
    container_name: sealskin
    environment:
      - PUID=1000
      - PGID=1000
      - TZ=Etc/UTC
      - "HOST_URL=sealskin.cheese"
    volumes:
      - ./volumes/sealskin-config:/config
      - ./volumes/sealskin-storage:/storage
      - /var/run/docker.sock:/var/run/docker.sock
    ports:
      - 8443:8443
      - 8000:8000 #optional
    restart: unless-stopped
EOF
docker compose up -d

Container logs

[..]
sealskin  | [2026-01-23 10:33:22] [INFO] [app.api] Successfully cached autostart script for 'webcord-wayland' from store 'SealSkin Apps'.
sealskin  | [2026-01-23 10:33:22] [INFO] [app.api] Successfully cached autostart script for 'mullvad-browser' from store 'SealSkin Apps'.
sealskin  | [2026-01-23 10:33:22] [INFO] [app.api] Successfully cached autostart script for 'zotero' from store 'SealSkin Apps'.
sealskin  | [2026-01-23 10:33:22] [INFO] [app.api] Successfully cached autostart script for 'opera-wayland' from store 'SealSkin Apps'.
sealskin  | [2026-01-23 10:33:22] [INFO] [app.api] Autostart script cache refresh complete.
sealskin  | [2026-01-23 10:33:22] [INFO] [app.api] Initial autostart script cache population complete.
sealskin  | [2026-01-23 10:33:22] [INFO] [app.api] Populating initial image metadata cache...
sealskin  | [2026-01-23 10:33:22] [INFO] [app.api] Image metadata cache populated.
sealskin  | [2026-01-23 10:34:45] [WARNING] [uvicorn.error] Invalid HTTP request received.
sealskin  | [2026-01-23 10:34:45] [WARNING] [uvicorn.error] Invalid HTTP request received.
sealskin  | [2026-01-23 10:34:45] [WARNING] [uvicorn.error] Invalid HTTP request received.
sealskin  | [2026-01-23 10:34:58] [WARNING] [uvicorn.error] Invalid HTTP request received.
sealskin  | [2026-01-23 10:34:58] [WARNING] [uvicorn.error] Invalid HTTP request received.
sealskin  | [2026-01-23 10:35:09] [WARNING] [uvicorn.error] Invalid HTTP request received.
sealskin  | [2026-01-23 10:35:09] [WARNING] [uvicorn.error] Invalid HTTP request received.

[thelamer]

You need a legit cert for that domain in /config/ssl

[Chaz6]

You need a legit cert for that domain in /config/ssl

Is that expected given that the same configuration works without issue using the Chrome extension?

[thelamer]

Yep, that is expected. Chrome can fall back to using http with E2EE firefox and the coming mobile apps for android and iOS cannot they need a legit domain and legit cert, there is no workaround.

Also as a side note if you are using a legit cert you do not need to forward port 8000 just 8443 (or whatever you have it set to)

And having a legit cert is free just FYI use something like duckdns and certbot to start with and see what else you want to do.

https://pypi.org/project/certbot-dns-duckdns/

[thelamer]

Closing as this is not a bug.