I am unable to start clamd service on CentOS Linux release 7.9.2009 (Core). Details are as follows. 

#systemctl start clamd@server.service
Job for clamd@server.service failed because the control process exited with error code. See "systemctl status clamd@server.service" and "journalctl -xe" for details.

# ls -l /etc/clamd.d/
total 68
-rw-r--r-- 1 root root 12110 Feb 27  2020 clamsmtp.conf
-rw-r--r-- 1 root root 26647 Jul 19 23:58 scan.conf
-rw-r--r-- 1 root root 26648 Jul 19 23:57 scan.conf.2021-07-19

# cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)

# rpm -qa | grep clam
clamav-0.103.3-1.el7.x86_64
clamsmtp-1.10-14.el7.x86_64
clamav-devel-0.103.3-1.el7.x86_64
clamav-update-0.103.3-1.el7.x86_64
clamd-0.103.3-1.el7.x86_64
clamav-lib-0.103.3-1.el7.x86_64
clamav-data-0.103.3-1.el7.noarch
clamav-filesystem-0.103.3-1.el7.noarch
#

Jul 20 00:01:57 testdeveloperportal systemd: Starting clamd scanner (server) daemon...
Jul 20 00:01:57 testdeveloperportal clamd: ERROR: Can't open/parse the config file /etc/clamd.d/server.conf
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service: control process exited, code=exited status=1
Jul 20 00:01:57 testdeveloperportal systemd: Failed to start clamd scanner (server) daemon.
Jul 20 00:01:57 testdeveloperportal systemd: Unit clamd@server.service entered failed state.
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service failed.
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service holdoff time over, scheduling restart.
Jul 20 00:01:57 testdeveloperportal systemd: Stopped clamd scanner (server) daemon.
Jul 20 00:01:57 testdeveloperportal systemd: Starting clamd scanner (server) daemon...
Jul 20 00:01:57 testdeveloperportal clamd: ERROR: Can't open/parse the config file /etc/clamd.d/server.conf
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service: control process exited, code=exited status=1
Jul 20 00:01:57 testdeveloperportal systemd: Failed to start clamd scanner (server) daemon.
Jul 20 00:01:57 testdeveloperportal systemd: Unit clamd@server.service entered failed state.
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service failed.
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service holdoff time over, scheduling restart.
Jul 20 00:01:57 testdeveloperportal systemd: Stopped clamd scanner (server) daemon.
Jul 20 00:01:57 testdeveloperportal systemd: Starting clamd scanner (server) daemon...
Jul 20 00:01:57 testdeveloperportal clamd: ERROR: Can't open/parse the config file /etc/clamd.d/server.conf
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service: control process exited, code=exited status=1
Jul 20 00:01:57 testdeveloperportal systemd: Failed to start clamd scanner (server) daemon.
Jul 20 00:01:57 testdeveloperportal systemd: Unit clamd@server.service entered failed state.
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service failed.
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service holdoff time over, scheduling restart.
Jul 20 00:01:57 testdeveloperportal systemd: Stopped clamd scanner (server) daemon.
Jul 20 00:01:57 testdeveloperportal systemd: Starting clamd scanner (server) daemon...
Jul 20 00:01:57 testdeveloperportal clamd: ERROR: Can't open/parse the config file /etc/clamd.d/server.conf
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service: control process exited, code=exited status=1
Jul 20 00:01:57 testdeveloperportal systemd: Failed to start clamd scanner (server) daemon.
Jul 20 00:01:57 testdeveloperportal systemd: Unit clamd@server.service entered failed state.
Jul 20 00:01:57 testdeveloperportal systemd: clamd@server.service failed.
Jul 20 00:01:58 testdeveloperportal systemd: clamd@server.service holdoff time over, scheduling restart.
Jul 20 00:01:58 testdeveloperportal systemd: Stopped clamd scanner (server) daemon.
Jul 20 00:01:58 testdeveloperportal systemd: Starting clamd scanner (server) daemon...
Jul 20 00:01:58 testdeveloperportal clamd: ERROR: Can't open/parse the config file /etc/clamd.d/server.conf
Jul 20 00:01:58 testdeveloperportal systemd: clamd@server.service: control process exited, code=exited status=1
Jul 20 00:01:58 testdeveloperportal systemd: Failed to start clamd scanner (server) daemon.
Jul 20 00:01:58 testdeveloperportal systemd: Unit clamd@server.service entered failed state.
Jul 20 00:01:58 testdeveloperportal systemd: clamd@server.service failed.
Jul 20 00:01:58 testdeveloperportal systemd: clamd@server.service holdoff time over, scheduling restart.
Jul 20 00:01:58 testdeveloperportal systemd: Stopped clamd scanner (server) daemon.
Jul 20 00:01:58 testdeveloperportal systemd: start request repeated too quickly for clamd@server.service
Jul 20 00:01:58 testdeveloperportal systemd: Failed to start clamd scanner (server) daemon.
Jul 20 00:01:58 testdeveloperportal systemd: Unit clamd@server.service entered failed state.
Jul 20 00:01:58 testdeveloperportal systemd: clamd@server.service failed.