Update 4/23/2024: We have now released April 2024 Hotfix Updates which address known issues in March 2024 SU updates.
Microsoft has released Security Updates (SUs) for vulnerabilities found in:
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Updated Apr 23, 2024
Version 8.0
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Microsoft
MicrosoftTed_Mittelstaedt dbkgict Terrymmd91 TimDJordan mati5000 Brianmsb ceantuco Peter2220 Tonaco dbran And anyone else asking about Outlook Mobile sign-in issues:
We believe that we have identified the problem causing this. It is related to a service side change that was just timed similarly to when release of on-prem updates were released but is completely unrelated to Exchange Server CU or SU updates. Rather, it is related to a Cloud Cache service side (see how this works here: Using hybrid Modern Authentication with Outlook for iOS and Android | Microsoft Learn). We are working with the relevant service team to address. We are still investigating the details of this but this would explain exactly what is going on.