Hi again,
DrCarsonBeckett: We did not change the config ourselves. The clamav package got updated on debians side and therefore it got updated with an apt-get upgrade (or apt upgrade). And as fulltilt already said, on some systems - an this should be the usual case - the system detects your config and asks if you want to use the new version or your currently using version of the configuration. Additional, you have the option to show the difference and check for yourself.
But this was not the case in some updates from fulltilt and it was not the case in my update. In these updates the question never got asked and the config is overridden by the clamav package itself. Reinstall from the clamav plugin doesn't solve this and as written above, the latest clamav update seems to be not fully compatible with the latest plugin version.
I can confirm that it's somewhat still working, but from time to time the error will be shown in the log.
So the question would be:
Nuxwin What is the correct way to handle this, until the new clamav plugin, which will be not free anymore, will be released? Should we stay in this situation until then, disable the clamav plugin, or is there any fix for the moment? Unfortunately the clamav readme from the i-mscp plugin is removed, therefore I wasn't able to check and fix the config change myself.
I still do not understand why the package update did not ask for the config change. For instance: The last update asked for exact the same case, when we updated e.g. the telegraf package. And since you usually have the option: Check the difference between the two and decide which config to use, you can protect yourself from any problems and add new configuration parts for yourself later.
The weird thing is, that the first error, which also appeared in the mail.err log file, is not there anymore so clamav seems to work for the moment.