Error in Plesk during the ClamAV update: downloadPatch: Can't apply patch

Symptoms

The following errors are received by email and when executing the freshclam command on the Plesk server:

CONFIG_TEXT: ERROR: cdiff_apply: lseek(desc, -350, SEEK_END) failed
ERROR: downloadPatch: Can't apply patch

Cause

A ClamAV database is absent in the directory /var/lib/clamav.

Resolution

1. Connect to the server via SSH.

2. Check the databases available:

   # ls -la /var/lib/clamav/*.cvd

   Note: There should be 3 files:
   bytecode.cvd
daily.cvd
main.cvd

3. Download the missing database using the native ClamAV utility:

   # freshclam

4. If the utility shows error and the required database is still absent, download the absent file from the link http://database.clamav.net/<database_name>.cvd (i.e. http://database.clamav.net/daily.cvd) and upload it on the server.

   Note: using wget utility to download the database may result in error 403. If it appears try downloading the database to your local PC first and then transfer it to the server, e.g. by using FTP client.

5. Set the proper permissions:

   # chown clamupdate:clamupdate /var/lib/clamav/daily.cvd
   # chmod 0644 /var/lib/clamav/daily.cvd