First, thanks for your help.
Yes the system has been restored from a backup (on the same machine). But before restoring the backup, some file might have been lost on the disk (not on the backup).
I’m pretty sure I have already tried the domain command line. I’ll try again tonight when I have access to the server.
If it doesn’t work, you suggest I switch to a self-signed certificate, and the back to a regular certificate ? Is that your point ?