Update Manager cannot fetch some packages

After a fresh install, I started up System -> Administration -> Upgrade Manager.

Pressing Check works fine, but pressing Install Updates fails after a little while. In the details it says it cannot download the following files.

sysvinit-utils i386 2.87dsf-4ubuntu.19.1
sysv-rc all 2.87dsf-4ubuntu.19.1
initscripts i386 2.87dsf-4ubuntu.19.1

The response for all 3 is a HTTP 404.

I worked around the problem by using apt-get update && apt-get upgrade in a terminal. Unexperienced users may not be able to figure out how to do this, even if they find my work around in the forum.