If you try to edit a file in the File Explorer as the wrong user, you get a green notification saying "File was updated", even if the file actually wasn't updated. This should show an error warning of what went wrong.
Secondary issue I noticed here - after editing the file as the ploi user (which failed - above), I was then taken back to /ploi/home instead of the directory I was working in, at /home/siteuser/templates/... etc etc.
Add error reporting to the File Explorer
Dennis moved item to board Planned3 months ago
Daryl moved item to project Panel Requests3 months ago
Daryl created the item3 months ago