Desktop client 3.1.2 installation: needs to close everything?

I attempted to upgrade NC desktop client from 3.1.1 to 3.1.2, and was greeted by message I never seen before:

The following applications are using files that need to be updated by this setup. You can let Setup Wizard close them and attempt to restart themor reboot the machine later.

Comodo Internet Security
Nod32 Antivirus
Double Commandeer
Windows Explorer

What the hell is this? Since when NC-client wants to update some files used by antivir or firewall? BTW, I tested 3.1.1 and 3.1.2, and this strange message comes only when installing 3.1.2 client. What was changed? Why suddenly NC-client needs to stop such critical services?

these files seem to be blocked by these applications. Not sure if the updater checks for these files and then your AV is alerted and takes a look at the files too blocking exclusive access to them.

On the changelog, I couldn’t see anything related to the update process: