Now that App Center is the default in Ubuntu "Find More in Software" no longer works

[AJenbo]

When trying to open an unknown URL or file type you get this:

Clicking the orange button gives you this:

[seb128]

Could you describe the steps that lead to that dialog? In which application do you try to open a file/and which type or url?

GTK has a deprecated gtkappchooserdialog widget but that hides the button if gnome-software is not installed
https://gitlab.gnome.org/GNOME/gtk/-/blob/main/gtk/deprecated/gtkappchooserdialog.c#L447

The portals do have the issue they are trying to start gnome-software without having a similar check so it's likely the issue described there (which would like impact a confined application trying to use an appchooser)

https://gitlab.gnome.org/GNOME/xdg-desktop-portal-gnome/-/blob/main/src/appchooserdialog.c#L185
and
https://github.com/flatpak/xdg-desktop-portal-gtk/blob/main/src/appchooserdialog.c#L215

Ideally we should fix those to try snap-store on Ubuntu as a first option if available (and update the command line arguments according), the corresponding launchpad report is https://bugs.launchpad.net/ubuntu/+source/xdg-desktop-portal-gtk/+bug/2058444

[AJenbo]

I tired opening a link that was using a custom protocol from the Snap version (default) of Firefox.

More specifically a phpstorm:// link so I would have expected the store to open and show PHPStorm as the solution.