"Open containing folder" in Firefox opens Thunar instead of default Nautilus

Question

After going through several already-answered questions on AskUbuntu and Unix's stackexchange, Firefox's "Open containing folder" option (when a file is downloaded) still opens folder in Thunar File Manager, even though my default file manager is Nautilus. (However, it's Nautilus that's opened when prompted to save a file, for example, meaning, I guess, that Firefox is somehow aware that Nautilus exists.) I'm on XFCE (Ubuntu 22) so I can't uninstall Thunar without causing core problems (already tried that).

Nautilus (under the name Files) is set a default File Manager. In the GUI of my "Applications by default" app, inode/directory and inode/mount-point are set to Files.

I've tried to modify every mimeapps.list and defaults.list and mimeinfo.cache files possible, every single one of them has the following line:

inode/directory=org.gnome.Nautilus.desktop

(Some of them have also [Default Applications] on the line before)

Except one mimeinfo.cache that has "Catfish" and "Thunar" after Nautilus. But removing mention of Thunar with sudo doesn't change anything.

I also updated /usr/share/dbus-1/services/org.freedesktop.FileManager1.service according to suggestions, that didn't change anything.

I've closed/reopened my user session, also restarted my computer, nothing changed.

What have I missed?

Please don't mark as duplicate, since none of the answers provided in below questions solutioned my problem:

• Change file manager used by Firefox on Lubuntu
• "Open containing folder" in Firefox does not use my default file manager
• How to force Firefox to open downloads with new default file manager (Nemo)?
• Make nemo the default file browser
• https://unix.stackexchange.com/questions/336982/how-to-avoid-a-program-taking-over-the-file-manager-when-opening-a-folder-in-tha/336984#336984
• https://unix.stackexchange.com/questions/333254/set-standard-file-browser-for-open-containing-folder
• Stop folders opening with different application than the file manager

Answer 1

Imagining this is related to my case:

Look at /usr/share/dbus-1/services/ and find:

 org.xfce.FileManager.service
 org.xfce.Thunar.FileManager1.service

Because I was using Dolphin on Kubuntu I had also org.kde.dolphin.FileManager1.service. I have copied the line SystemdService=plasma-dolphin.service from the "dolphin" file into the other two, replacing the corresponding "thunar" lines there.

In your case you should use the variables corresponding to your case, involving "nautilus".

They might look like so:

org.xfce.FileManager.service:

[D-BUS Service]
Name=org.xfce.FileManager
Exec=/usr/bin/Thunar --gapplication-service
SystemdService=nautilus.service

org.xfce.Thunar.FileManager1.service:

[D-BUS Service]
Name=org.freedesktop.FileManager1
Exec=/usr/bin/Thunar --gapplication-service
SystemdService=nautilus.service

I am not sure about org.gnome.Nautilus.service: but maybe something like:

[D-BUS Service]
Name=org.freedesktop.FileManager1
Exec=/usr/bin/nautilus --daemon
SystemdService=nautilus.service

---

Other solutions from my sources (see link), which I haven't tested but are confirmed to work:

• running killall Thunar at login

• running systemctl --user mask thunar

I think these solutions cannot be used on a desktop like Xfce (where Thunar is handling the desktop) without further settings that would fully replace Thunar's functions.