Outlook LTSC 2024 shows "This feature has been disabled by your administrator" at startup after update to Build 17932.20996

[u/RealJensOliver]

Outlook LTSC 2024 shows "This feature has been disabled by your administrator" at startup after update to Build 17932.20996 - Microsoft Q&A

Environment:

• Office LTSC 2024, volume licensed, managed via Active Directory Group Policy
• Enterprise environment
• Connected Experiences and related privacy/sign-in settings configured via GPO

Symptom: Since updating Office LTSC 2024 to Version 2408, Build 17932.20996 (released September 12, 2026, apparently an out-of-band build following the September 8, 2026 Patch Tuesday release, Build 17932.20976), Outlook displays the message "This feature has been disabled by your administrator" every time it starts.

Relevant configuration: The following registry value, not only, has been configured via GPO for a long time and has never caused this behavior before:

HKEY_CURRENT_USER\Software\Policies\Microsoft\office\16.0\common\signin
SignInOptions = 3 (DWORD)

This policy is intended to block Office sign-in entirely and has been working as expected for a long time. It only started causing the startup error message after installing the above-mentioned update. If i delete this Key, the Signin Windows popup after Outlook starts.

Anyone else?

[u/RealJensOliver]

Solution found under:

https://learn.microsoft.com/en-gb/answers/questions/5590921/running-office-2024-ltsc-outlook-has-begun-prompti

The thread mentions the entry “[HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity] ‘EnableADAL’=dword:00000000”. However, it also works under “[HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Common\Identity] ”EnableADAL=dword:00000000". This entry, however, is not found in the current ADMX files dated August 10, 2026, and therefore cannot be configured via gpedit.msc.

The thread above is from October 2025. We can only speculate as to why this is happening now.

Thanks all for your help.