ROXTerm is no longer under development, see this thread and bug #125, but there is some hope of resurrecting it.
I'm not familiar with Fedora, but I believe it's aimed to be close to the bleeding edge, so it's most likely using GTK >= 3.20, which usually breaks ROXTerm quite badly, so I would have expected you to have more woes before you got as far as trying to launch an editor.
Perhaps you're using Wayland? My best guess is that roxterm is setting something in the environment incompatinly, eg DISPLAY, and that's why it can't launch other GTK apps. Try comparing its value in roxterm and gnome-terminal, and if they're different, prefix your commands with DISPLAY=... with the value from gnome-terminal.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Fresh Fedora 25 install. Installed ROXTerm... Can't launch applications from command line anymore.
$ geany
Geany: cannot open display
$ gedit
** (gedit:30254): WARNING **: Could not open X display
$ evince
** (evince:30291): WARNING **: Could not open X display
Anyone else seen this? Any idea how I can fix it?
Thanks in advance!
ROXTerm is no longer under development, see this thread and bug #125, but there is some hope of resurrecting it.
I'm not familiar with Fedora, but I believe it's aimed to be close to the bleeding edge, so it's most likely using GTK >= 3.20, which usually breaks ROXTerm quite badly, so I would have expected you to have more woes before you got as far as trying to launch an editor.
Perhaps you're using Wayland? My best guess is that roxterm is setting something in the environment incompatinly, eg DISPLAY, and that's why it can't launch other GTK apps. Try comparing its value in roxterm and gnome-terminal, and if they're different, prefix your commands with DISPLAY=... with the value from gnome-terminal.