Official issue: https://github.com/npm/registry/issues/255
Official status: https://status.npmjs.org/incidents/41zfb8qpvrdj
Several packages including “require-from-string” are currently unavailable. We are aware of the issue and are working to restore the affected user and packages. Please do not attempt to republish packages, as this will hinder our progress in restoring them.
Update from NPM:
Resolved
We apologize for the temporary unavailability of some packages. We will be publishing a comprehensive post-mortem update in the next few days.
Posted Jan 06, 2018 – 23:14 UTC