Firefox Nightly

My Distribution is Debian 10 (oldstable) had installed ESR using apt and nightly using snap when i try to download(if i select ask where to save option) nothing works on nightly whereas if i set a default folder for downloading it works ESR is unaffected by any of this any idea why this happens by nothing works I mean that no window appears that would make select the directory for saving the file

This works for me here on Ubuntu 21.10 (the “Always ask where to save files” option is respected and a file dialog pops up).

I just tested in a Debian 10 VM, and I can confirm your observations. I’m seeing the following error:

(firefox-nightly:2479): Gtk-WARNING **: 18:20:35.221: Can't open portal file chooser: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.portal.Desktop was not provided by any .service files

The problem is resolved after installing xdg-desktop-portal-gtk.