This article relates to our Simple Sign-On (SSO) product, but may also help solve a problem in other SSO systems.
Situation: A user attempts to SSO into Office 356 and they're presented with a blank white page and are unable to progress any further.
This problem is common associated with certain web-filters and we've found is particularly common with the Lightspeed web-filter. But fret ye not, there's an easy fix.
The issue is that the web-filter is blocking the browser from resolving secure.aadcdn.microsoftonline-p.com
You can understand why - it does look like a suspicious address at first glance. and Lightspeed started categorizing this Microsoft address as malware. But as you can see in this post of URLs and IPs it is a legit address: https://support.office.com/en-us/article/office-365-urls-and-ip-address-ranges-8548a211-3fe7-47cb-abb1-355ea5aa88a2
To solve this you can simply change forwarders in Lightspeed to 126.96.36.199
If you have any questions or need any help please feel free to contact firstname.lastname@example.org