Virus definition update failed (downloading 0 bytes)

Started happening about a week ago, every time I try to update, it shows “downloading [0 bytes]” for a split second and then ‘failed’
I was on version 5.10 but then I updated to 5.12 and it actually updated fine on the first run, but 2 days later it started doing the error again.
as far as i know this version is still supported, in terms of AV updates and stuff, any idea what could be wrong?
adding that i did try to manually download new definition file but the program seems to ignore it and re-downloads (or reapplies?) the old definition file instead.

versions 5.xx apparently not receive updates…

sorry my english!

Hi mataku,

CIS 5.10 is very old version. You can’t update from 5.10 to the latest CIS. Please use this link to install CIS

Thank you

So i’ve reluctantly upgraded CIS to the latest version, and yet, still unable to update virus definition.

Could you please add “” to “Proxy and Host Settings” and see if it works.
Advanced Settings → Updates → Proxy and Host Settings → Servers