[German]The security update KB5082063, released on April 14, 2026, for Windows Server 2025, causes installation error 0x800F0983 on some systems. In addition, the April 2026 updates caused reboot errors on domain controllers running Windows Server 2016–2026, Microsoft released out-of-band updates (including KB5091157) on April 19, 2026, to resolve installation error 0x800F0983 and the reboot error.
Installation Error 0x800F0983 and Reboot Loop
On April 14, 2026, Microsoft released security update KB5082063 for Windows Server 2025. I had reported on the security updates provided by Microsoft for Windows Server in the blog post " Patchday: Windows Server-Updates (April 14, 2026)." This security update KB5082063 causes installation errors on some systems. Last week, via the patchmanagement.org mailing list, I received a notification from Microsoft stating that the KB5082063 update for Windows Server 2025 triggers error 0x800F0983 during installation.
I reported on this issue in the post "Select Windows Server 2025 Update KB5082063: Error 0x80073712 due to Media Player; and Error 0x800F0983 Windows Server 2025 Update KB5082063: Error 0x80073712 due to Media Player; and Error 0x800F0983." Furthermore, Microsoft had to admit that the April 2026 updates caused reboots on domain controllers running Windows Server 2016 through 2025 (see Windows Server 2016–2025: April 2026 Updates are causing domain controller reboots).
Out-of-Band Updates for Windows Server
On April 19, 2026, Microsoft released several out-of-band updates (including KB5091157) to fix installation error 0x800F0983 and the reboot issue. This Microsoft webpage states that for Windows Server 2025, the cumulative update KB5091157 was released to address the following issues:
- [Domain controllers (known issue)] Fixed: After installing the April 14, 2026, Windows security update (KB5082063) and restarting, domain controllers with multi-domain forests that use Privileged Access Management (PAM), might experience startup issues. In some cases, Local Security Authority Subsystem Service (LSASS) might stop responding, leading to repeated restarts, and preventing authentication and directory services, which can make the domain unavailable.
- [Windows update installation] Fixed: A small number of Windows Server 2025 devices might fail to install the April 14, 2026, Windows security update (KB5082063). When this issue occurs, affected devices might display one of the following error messages: "Install error: 0x800F0983" or "Some update files are missing or have problems. We'll try to download the update again later. Error code: 0x80073712."
The following updates have been released for other versions of Windows Server:
- KB5091571 for Windows Server 23H2
- KB5091575 for Windows Server 2022
- KB509157 for Windows Server Version 2019
- KB509157 for Windows Server Version 2016
However, as I gathered from the description, these updates exclusively address the domain controller reboot issue. Microsoft has documented the case in Microsoft Admin Center under MC1285472 (see also this post). There are also the following hotpatches:
- Windows Server 2025 Datacenter: Azure Edition: Hotpatch KB5091470 (OS Build 26100.32704) Out-of-band
- Windows Server 2022 Datacenter: Azure Edition: Hotpatch KB5091576 (OS Build 20348.5029) Out-of-band
Similar articles [use build-in translation]:
Microsoft Security Update Summary (14. April 2026)
Patchday: Windows 10/11 Updates (14. April 2026)
Patchday: Windows Server-Updates (14. April 2026)
Patchday: Microsoft Office Updates (14. April 2026)
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Windows Server 2025: Update KB5082063 liefert Error 0x800F0983, 0x80073712
Windows Server 2025: Fehler 0x80073712 bei KB5082063 durch Media Player-Sprachpakete
Windows Server 2016-2025: Reboot von Domain Controllern durch April 2026-Update (KB5082063 etc.)
Windows April 2026-Updates verursachen Anmelde-Probleme
Ungewollte Windows Server-Upgrades (2019 und 2022) auf 2025
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