Comment 2 for bug 1760079

I managed to fix the problem by opening the Synaptic Package Manager, then selecting all installed ClamAV and ClamTK packages, for complete deletion, including configuration files and installation logs, in addition to all the suggested packages.
Once that was done, I did a fresh installation of ClamTK and all the recommended and suggested packages.
Then I had to recreate the file 'clamd.conf' in etc / clamav, and finally, everything worked again normally.