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Microsoft 365 Desktop App Installation Blocked Due to Authentication Misconfiguration

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1 unique sources, 2 articles

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Microsoft is addressing a bug preventing installation of Microsoft 365 desktop apps on Windows devices. The issue stems from misconfigured authentication components in versions 2508 (Build 19127.20358) and 2507 (Build 19029.20294). The bug has been impacting users since November 2nd, causing Office Client issues. Microsoft has developed and is testing a fix, with an update on progress expected by 6:30 PM UTC today. The incident, tagged as OP1192004, is considered critical with noticeable user impact. Additionally, Microsoft is resolving a separate issue (MO1176905) affecting access to multiple Microsoft 365 services for some admins and users.

Timeline

  1. 04.12.2025 15:18 1 articles · 23h ago

    Microsoft resolves Excel email attachment issue in new Outlook client

    Microsoft is also working to resolve a known issue that blocks some users from opening Excel email attachments in the new Outlook client due to an encoding error in Excel file names.

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  2. 17.11.2025 16:54 2 articles · 17d ago

    Microsoft 365 Desktop App Installation Blocked Due to Authentication Misconfiguration

    Microsoft identified a bug preventing the installation of Microsoft 365 desktop apps on Windows devices due to misconfigured authentication components. The bug has been impacting users since November 2nd, causing Office Client issues. Microsoft has developed and is testing a fix, with an update on progress expected by 6:30 PM UTC today. The incident is classified as critical with noticeable user impact.

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Information Snippets

Similar Happenings

Microsoft Outlook New Client Excel Attachment Opening Issue

Microsoft is addressing a known issue affecting the new Outlook client, preventing users from opening Excel attachments with non-ASCII characters in the file name. The bug, identified on November 23rd, triggers an error message prompting users to try opening the file again later. Microsoft has deployed a fix but it has not yet reached all affected users. The issue has been tagged as an advisory, indicating limited scope or impact. Users are advised to use Outlook on the web or download the file to open it locally.

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