1. Remove the /var/run/sssd/sssd.pid file if exists else remove /var/run/sssd.pid file.
# rm /var/run/sssd/sssd.pid
OR
# rm /var/run/sssd.pid
2. Remove ‘sssd‘ file inside /var/lock/subsys directory if exists.
# rm /var/lock/subsys/sssd
3. Stop the sssd service
# systemctl stop sssd
4. Start sssd service
# systemctl start sssd