Ah, I see. We have been able to reproduce this - it looks like a regression in handling the feed-specific npm adduser URL. We've also always handled the /siteroot/-/... one as well because npm used to always use that regardless of the repository URL. I think that changed some time around npm 2.7 when we added the second handler. Regardless, we've already fixed this internally (again), and will be releasing the fix as part of ProGet 3.8.1 likely some time tomorrow. Thanks for the help!

This issue has been resolved in ProGet 3.8.1.

npm changes its access URLs a lot, and from looking through its checkin history it usually seems to be accidental. ProGet currently supports two URLs for adduser: /-/user/org.couchdb.user[...] or /npm/[FEED]/-/user/org.couchdb.user[...] I've never seen any version of npm use a ~ instead of a - before... What version did you upgrade from?

We have not had other users report this problem, nor have we seen it during testing. You can try running the service interactively (just stop the WIndows Service, then run the .exe file), and see what happens. Also worth noting, make sure that all the errors in the log are deleted before the packages start indexing again.