The product group released the November 2025 Cumulative Update for Office Online Server.
The KB article for November 2025 CU will be available at the following Location in a couple of hours:
- KB 5002801 – November 2025 Update for Office Online Server
The download for November 2025 CU is available through the following link:
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Hello Stefan,
We have a single server with Office Online server that is not connected to SharePoint 2019 farm. Could you please share if we have any install instructions on how to apply this update in the office server.
Thank you for the help.
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Hi Ram,
please follow this guidance:
https://learn.microsoft.com/en-us/officeonlineserver/apply-software-updates-to-office-online-server
Cheers,
Stefan
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Strange issue: After installing this OOS Update file, the IIS Sites entries disappeared from the IISManager.
I restored “applicationHost.config” from the backup (%SystemDrive%\inetpub\history) into %windir%\System32\inetsrv\config and execute IISReset
After this, all was fine again.
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Issue after update.
Following installation of OOS update, and reinstalling OOS farm, users have reported issues opening both PPT and Word docs from SharePoint. Excel and PDF docs open fine.
PPT files are showing a “server error in ‘p’ application” and Word Online won’t open files
The same update has been installed on other OOS farms, and is working without issue.
Any other experiences of this nature?
Thanks
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Hello,
I have OOS2016 on Windows Server 2016 version from 2018 (KB4011024).
When I start the update, it says:
“Security update for Microsoft Office Online Server (KB5002801) 64-bit Edition
The expected product version was not found on the system.”
Machine is not joined to the farm.
I believe there is a new basic version Like OOS2019 or update from before which needs to be installed before I continue?
Thank you!
Br,
Martin