Firefox seems adamant on using Thunar instead of the new default (PCManFM-Qt), to open downloaded files and such. Other programs respected the change instantly.
I’ve tried to log out and back in, restart and even reinstalling. Thoughts?
XFCE - X11 - Native Firefox package.
I’m not too sure but this might help, though the parts I read said not possible
Thunar is the issue. This is my post on MX Linux forums. If you are using Xfce, Thunar is a requirement, so you can either force uninstall it with -Rdd or mask it — IF you don’t want to uninstall it. Or you can do what the user on the MX Forum did.
Link: https://forum.mxlinux.org/viewtopic.php?t=88007
I’ve had this issue before on Cinnamon and Openbox. From my experience and memory it was a combination of many steps to get it to finally work for most things, but it would just not work for Firefox, so I uninstalled Thunar.
You’ll have to probably do the same steps I did.
- Edited the mime apps list and manually added my preferred file manager.
- Right-clicked folders, chose “Open in” clicked the checkbox for saving my preferred file manager as default
- And what you did - used the standard Settings Editor (which is all I should’ve needed)
- Learned about handlr and all the other methods because Thunar was being a beeswax.
https://wiki.archlinux.org/title/Default_applications
- And even did the command line method: xdg-mime default nemo.desktop inode/directory
Thunar doesn’t play nice with other file managers in my experience, so I always uninstall it if it comes with a distro.
Of course, since you are using Xfce, you may not be able to uninstall Thunar, if you wanted to do so.Thunar, god of annoyance.
PS: If MX Linux has a custom menu that points to Thunar, but the option only says “File Manager” as an example, it would mean that you also need to edit the config file for that custom menu. An easy way to find the config file is to open up your ~.config/ folder in Kate (for instance) and search all files in all subfolders for “thunar”.
Is directly thunar somewhere in your firefox settings mentioned?
Have a look at Settings - General - Files and Applications
Maybe in the section for Applications you find an entry like Open with Thunar or similar. To change that entry, click on the entry and choose from list.
If you are using Xfce, Thunar is a requirement.
But not in Debian based XFCE-s.
I can remove Thunar there and desktop is still functional as opposed to the arch based ones.
Only File manager have to be modified in the Default Applications.
Edit:
Having uninstalled thunar with -Rdd the xfdesktop is dead. No clicks allowed, no background.
What does @dnn mean by masking?
It is strange to see considering Thunar is “component-based”, so there really should be no hard requirement like that. In this case, the hard requirement is to xfdesktop.
In any case, this is still a Thunar-specific problem. I went on a file manager journey a few years back, and only Thunar had this issue where it felt like it must be the default no matter which DE/WM I was using. So, I showed it the door. 
Well, there you go. Can’t do without Thunar then if the desktop is dead. Almost like using a tiling WM. I don’t use Xfce, so more than anything, that suggestion is for users who also don’t use it.
I used the wrong term. I should’ve said “override” or symlink.
And meaning like this:
mkdir -p ~/.local/share/dbus-1/services
cp /usr/share/dbus-1/services/org.freedesktop.FileManager1.service ~/.local/share/dbus-1/services/
nano ~/.local/share/dbus-1/services/org.freedesktop.FileManager1.service
Add the following line:
Exec=preferredFileManager --gapplication-service
OR
mkdir -p ~/.local/share/dbus-1/services
ln -sf /usr/share/dbus-1/services/preferredFileManager.FileManager1.service \ ~/.local/share/dbus-1/services/org.freedesktop.FileManager1.service
Log out and log in.
Replace “preferredFileManager” with the name of the actual file manager in lower case. So, "pcmanfm", "nemo", "dolphin", etc.
Use the below command to find the correct name. Look for FileManager1.service:
ls /usr/share/dbus-1/services/*File*
PS: Unless you are using a static release distro with older paradigms, use the second method. The file org.freedesktop.FileManager1.service likely doesn’t exist on rolling release distros nor even recent static releases.