Some users at our hosted site (discourse.julialang.org) have reported just seeing a white page when trying to access the site this morning, with their console logs littered with the error:
Failed to load resource: net::ERR_CERT_AUTHORITY_INVALID
That sounds like that the corporate environment CA bundle doesn’t trust the current root certificate for Let’s Encrypt. It’s something that can happen with outdated CA bundles or outdated OSs.