This can be safely ignored.
What’s happening is that virtualbox-guest-utils is asking VirtualBox for the time. Which is blocked as per Whonix default VirtualBox VM settings.
Previously this was disabled inside the VM too through pacakge https://github.com/Whonix/vbox-disable-timesync but this was recently disabled since it causes more issues than it does good. This error message we have to live with but it doesn’t break anything.