Yes, seems to be an issue with CloudFlare's JS challenge page interrupting the resource request: <a href="https://github.com/mjackson/unpkg/issues/343" rel="nofollow">https://github.com/mjackson/unpkg/issues/343</a><p>I was able to hastily fix this in production by migrating to jsdeliver: <a href="https://www.jsdelivr.com/unpkg" rel="nofollow">https://www.jsdelivr.com/unpkg</a>