After installing Virtualmin and configuring it a check is done to make sure the configuration works. One error that I've seen come up at times is the following:

    The ClamAV program clamscan does not appear to be working properly :

    LibClamAV Error: cli_loaddbdir(): No supported database files found in /var/lib/clamav ERROR: Can't open file or directory

As you can see, the error mentions missing database files needed by the ClamAV program.

The way to get the needed database file(s) and to make the error go away is to run the following commands as root:

/etc/init.d/clamav-freshclam stop

... then run....

freshclam

... that will result in the database being downloaded. And finally run...

/etc/init.d/clamav-freshclam start

Now when you check your Virtualmin configuration, hopefully this time you won't see any ClamAV errors!