I\'m trying to reinstall it, because it has problems. For example, I can\'t install Chromium because mongodb-org-server is not configured. But I can\'t even remove it for the sa
To avoid that sort of problems you should install software only from native Debian repositories. Unfortunately it is not unusual when sloppy/incompetent 3rd party packages are responsible for such troubles.
To recover try removing file /var/lib/dpkg/info/mongodb-org-server.postinst
before attempting to apt-get purge mongodb
.