For what it’s worth, I’m seeing the same error on my self-hosted Ghost this evening.
I installed it a week or two ago (version 5.71.0), successfully did a ghost update to 5.72.0 about a week later… but now ghost update is failing. (Ghost itself has been working great all this time.)
Same
error "components/tryghost-admin-x-design-system-5.73.0.tgz": Tarball is not in network and can not be located in cache
as you’re seeing.
Also, I also just tried to do a fresh ghost install in another directory for another new blog site and that seems to be failing with the same error.
Tried the ghost buster cache clear, also sudo npm install yarn -g (which gets a command-line yarn) but no joy.
Puzzled… hoping it’s an “upstream issue” and someone will do some magic that’ll fix it.