Hello I have the identical Problem.
Debian 9 on vmware
But i had a further Error on first try, it wrote something like couldnt copy file from to.
After i pressed retry i got this error on Picture.
559 #error( sprintf( "Couldn't initialize ClamAV databases: %s", $stderr 'Unknown error' ) ) if $rs;
Now i cant uninstall clamav or something else.
Thanks very much.