Windows 11 25H2 — cumulative updates deadlock at offline commit (CBS_E_HANG_DETECTED 0x800f0920); survives in-place upgrade repair

Lin 20 Reputation points
2026-08-29T07:57:22.24+00:00

Windows_Update_Failure_Summary2.pdf

Hi,

  1. The failure description (hangs ~96-98%, rolls back after ~1hr, since July 2026)
  2. The error codes (0x800f0920 / 0x800f0845)
  3. The Procmon finding — TrustedInstaller loads the servicing stack, spawns worker threads, then goes completely silent with zero I/O for hours. This is your most compelling detail and it's currently invisible.
  4. The bullet list of what's been ruled out (SFC, ScanHealth, MemTest 48/48, chkdsk, no filter drivers, no pending.xml, BitLocker off)
  5. In-place upgrade from ISO completed successfully and the next cumulative still deadlocked — the fact that makes this non-routine
  6. DISM /Add-Package staged it successfully but it failed to commit — isolates the failure to the offline commit stage specifically

Attached in the PDF is the entire investigation done so far with no success. Hopefully someone here has more ideas how to try to fix this.

Thank you!

Windows for home | Windows 11 | Windows update
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Answer accepted by question author
Kai-H 26,385 Reputation points Microsoft External Staff Moderator
2026-08-30T07:59:21.64+00:00

Hi, Lin

The evidence in your PDF attachment points to a servicing deadlock during the reboot commit phase, not a normal download, cache, or file-corruption problem. Since the in-place repair also failed, repeating SFC, DISM, or update-component resets is unlikely to help.

Here are some suggestions you can try:

Restore BlockTimeIncrement to its default value. Extending the timeout only delays rollback when TrustedInstaller has stopped making progress.

Open Feedback Hub with Windows key + F, select Report a problem, enable Recreate my problem, and reproduce one update attempt. Attach the PDF, CBS logs from C:\Windows\Logs\CBS, Windows Update logs, and the Procmon boot log. Include “offline CBS commit deadlock” and both error codes in the title. Feedback Hub is the correct route for reporting reproducible Windows defects.

Reopen the support case and specifically request escalation to the Windows servicing/CBS team. Emphasize that DISM staging succeeds, but reboot commit deadlocks even after an in-place upgrade.

If an immediate fix is required, back up everything and perform a true clean installation by deleting the Windows partitions during Setup. This is different from another repair install and is the only meaningful local recovery step still left.

Thank you for your patience in reading, I hope this information has been helpful to you. 

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  1. Lin 20 Reputation points
    2026-08-31T09:47:52.0366667+00:00

    Thank you for the suggestions, will try the Feedback Hub and Support route and if all fails, will try the clean install.

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