SSSD could not load the configuration database No such file or directory

SSSD couldn’t load the configuration database [2]: No such file or directory

You may encounter this issue when you upgrade from Ubuntu 16.04 to Ubuntu 18.04, or upgrading through any Ubuntu versions. The SSSD service might not start. Most probably you might be missing the configuration file /etc/sssd/sssd.conf.

You can check if that configuration file exists.Try this if the file is missing:
$ sudo cp /usr/lib/x86_64-linux-gnu/sssd/conf/sssd.conf /etc/sssd/
$ sudo chmod 600 /etc/sssd/sssd.conf
$ sudo systemctl restart sssd.service

Kindly comment below if it works for you.