Although the npm client supports scoped packages, the public npm registry does not yet fully support them. We put code in place to prevent packages with scopes being accidentally pushed to the registry before we had completed the necessary work, but a bug in that code allowed 2 scoped packages to be published.
This broke some down-stream follower applications -- we expected that would happen, which is why we hadn't intended to allow scoped packages to publish yet. The bug that allowed the 2 packages in has been fixed, and those 2 packages deleted. If you run a follower, you should confirm that you are up to date and skip both the revs including the scoped packages and if necessary also the revs deleting them.
Our apologies for this incident. Scoped packages are coming to the public registry later this year, but will require explicitly switching to a new upstream host to avoid this kind of incompatibility.