Hi to all that can use this advice that took me quite a while to solve
it.

The problem was that while performing the command crontab -e and saving
the file, I got the error "error in message queue open"

The problem was that the crontab binary under /bin/crontab missed the
set user id bit after some hardening kit installation.

I corrected it by performing the command chmod +s /bin/crontab