Neither of the "steamtinkerlaunch" addon's modding features (Mod Organizer 2 and Vortex) install or work.

**Game information**

All games.

**Distribution name and version where applicable**

```
❯ cat /etc/os-release
BUG_REPORT_URL="https://github.com/NixOS/nixpkgs/issues"
BUILD_ID="22.11pre414197.fd54651f5ff"
DOCUMENTATION_URL="https://nixos.org/learn.html"
HOME_URL="https://nixos.org/"
ID=nixos
LOGO="nix-snowflake"
NAME=NixOS
PRETTY_NAME="NixOS 22.11 (Raccoon)"
SUPPORT_URL="https://nixos.org/community.html"
VERSION="22.11 (Raccoon)"
VERSION_CODENAME=raccoon
VERSION_ID="22.11"
```

**Flatpak info**

```
❯ flatpak --version
Flatpak 1.12.7
❯ flatpak --gl-drivers
nvidia-515-49-15
default
host
```

**Problem description**

Window to download Vortex opens but flashes a message about a wrong checksum (blank) when another was expected. I'm guessing the download failed and it simply couldn't checksum anything.

For Mod Organizer 2, window to download it opens up repeatedly and errors out repeatedly, too fast to read why. Then it gives up.

If you can point me to where a logfile for this would be, I'll add it here.

I'm guessing there's a file/directory access permission issue at either the Linux level or Flatpak level, but beyond that, not sure how to proceed. I'm relatively new to Flatpaks, although I understand the concept in theory.

**Does this issue reproduce with native Steam**

I haven't tested. Native Steam on NixOS is too flaky to use for most of my games currently, so I abandoned it.

Let me know how I can help further troubleshoot!

The report names steamtinkerlaunch's Vortex and Mod Organizer 2 download flows on NixOS 22.11 with Flatpak Steam, but provides no repository file, test, entry point, or log. Start by collecting the relevant Steam and steamtinkerlaunch logs and reproducing both failures; done means identifying the download or permission cause and confirming both modding features work.

Written by the indexing model from the issue text.