I recently had my office PC upgraded from ubuntu 14.04 to 18.04, with the XFCE interface (v4.12) installed. I dislike the standard file browser (thunar) so used one of the answers to this thread to change to nautilus. That worked and nautilus opens now when I double click on a folder.
However, nautilus will not open files. If I browse to a directory an click on, say, a text file, then the nautilus window briefly flashes and nothing else happens. Files opened fine in thunar.
The weird thing is that if I keep the nautilus window open and then use exo-preferred-applications to switch the default file manager back to thunar then nautilus can open files.
Does anyone have an idea what could be wrong here? It's an odd error.