Nautilus slow/unresponding/crashing

[Andrea Vai <andrea vai unipv it>]

Hi,
  from time to time (actually, very often in the last days, and almost
always today) Nautilus hangs and does not respond, and sometimes
crashes, even when I try to do simple actions (open a folder in a new
tab, copy a file, etc.).

Now I can almost reproduce the problem: make a copy of a 2 MB PDF file
in a folder containing less than 20 items takes more than 30 seconds.

Sometimes, the action is not performed and Nautilus crashes.

Terminal command "ls -l" in the affected directory runs fine.

BTW, there are many "affected directories", not just one.

dmesg shows nothing.

Running nautilus in a terminal window (in a "crash" case) shows

$ nautilus
sys:1: PyGIWarning: Nautilus was imported without specifying a version
first. Use gi.require_version('Nautilus', '3.0') before import to
ensure that the right version gets loaded.
Gdk-Message: 09:37:53.604: Lost connection to Wayland compositor.

Could anybody please help me to debug and solve it?

Thank you very much,
Andrea

Running Nautilus 3.28.1-stable in Fedora 28 desktop