User Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0 Build ID: 20160623084759 Steps to reproduce: Save a file OR open the containing folder from the downloads window. Using Fedora 24 with Cinnamon 3.0.6. Actual results: Firefox opens Nemo, which is not my default file manager. Expected results: Firefox should have opened Thunar, which is set as my default file manager on Fedora 24 + Cinnamon via mimeapps.list and mimeinfo.cache and modifications to .desktop files. This is a known problem: http://www.linuxquestions.org/questions/linux-software-2/firefox-iceweasel-workaround-open-containing-folder-with-user-defined-filemanager-903126/
Hi. I have the same issue (years ongoing), but I would like to add something to this bug report. I've noted that in Nightly 53.0a1 the Downloads pane action "Open Downloads Folder" opens the Downloads directory in the default file manager, while the icon next to a download ("Open Containing Folder") opens the directory in the wrong file manager. This is probably helpful to fix the issue.
I'm seeing this issue as well. I'm using Fedora 25 51.0.1 and gnome. When I open folders, I get Dolphin instead of Nautilus.
I'm also seeing this issue. I'm using Kubuntu 14.04.5 LTS and Firefox 54.0 (64-bit). Firefox just refuses to use Dolphin (system default) - even after changing MIME fies, etc... Also I get the same problem with Thunderbird 52.1.1 (64-bit). It looks like a general Mozilla app Linux bug