Wsus and Windows 11 25H2 Asus clients sync successfully but never report status

Marco 61 Reputation points
2026-07-21T14:50:55.3066667+00:00

Hello,

I'm troubleshooting a WSUS reporting issue that started immediately after installing the July 2026 cumulative updates on a Windows Server 2022 WSUS server and Asus Client

Environment

  • WSUS on Windows Server 2022
  • IIS 10
  • HTTPS (8531)
  • Clients: Windows 11 build 26200.65792
  • WSUS version: 10.0.20348.1

Symptoms

Affected clients:

  • Continue to contact WSUS successfully
  • Appear in the WSUS console
  • Can scan for updates
  • Can download updates
  • Show an updated Last Contact
  • Remain stuck on "Not Yet Reported"
  • Last Status Report stopped updating on 16 July 2026Hello, I'm troubleshooting a WSUS reporting issue that started immediately after installing the July 2026 cumulative updates on a Windows Server 2022 WSUS server.

    Environment

    • WSUS on Windows Server 2022
    • IIS 10
    • HTTPS (8531)
    • Clients: Windows 11 build 26200.65792
    • WSUS version: 10.0.20348.1

    Symptoms

    Affected clients:
    • Continue to contact WSUS successfully
    • Appear in the WSUS console
    • Can scan for updates
    • Can download updates
    • Show an updated Last Contact
    • Remain stuck on "Not Yet Reported"
    • Last Status Report stopped updating on 16 July 2026

Exemple:

  • Last Contact: 21/07/2026
  • Last Status Report: 16/07/2026

The issue started immediately after installing the July 2026 cumulative updates on the WSUS server.

Server log: C:\Program Files\Update Services\LogFiles\SoftwareDistribution.log

ReportingEvent.ValidateMiscData
ValidateMiscData: Rejecting MiscData entry with empty or whitespace-only value: t=
WebService.ValidateEventBatch
Event in batch failed to validate.
Exception: MiscData entry has empty or whitespace-only value: t=
ComputerBrand=[ASUSTeK COMPUTER INC.]
ComputerModel=[ASUS EXPERTBOOK B1502CVA_B1502CV]

OSVersion=[10.0.26200.65792.0.0.0.0.0]

miscData=[
t=
...
]

What has been checked

  • GPO configuration OK
  • WUServer/WUStatusServer OK
  • SSL certificate OK
  • IIS OK
  • Clients reach WSUS correctly
  • Resetting SusClientId does not help
  • Removing/recreating client objects in WSUS does not help
  • Other vendors (HP, Dell, etc.) continue reporting normally
Windows for business | Windows Server | Devices and deployment | System management components

3 answers

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  1. Domic Vo 34,330 Reputation points Independent Advisor
    2026-07-21T15:20:56.3066667+00:00

    Hello,

    The behavior you’re seeing is tied directly to the July 2026 cumulative update on Windows Server 2022. The WSUS server is still handling synchronization, downloads, and client contact correctly, but the reporting pipeline is breaking at the validation stage. The log entries you shared (ValidateMiscData: Rejecting MiscData entry with empty or whitespace-only value: t=) confirm that the WSUS reporting web service is rejecting status reports from affected ASUS clients because of malformed MiscData fields. This explains why “Last Contact” updates but “Last Status Report” remains frozen.

    The fact that HP and Dell clients continue reporting normally points to a vendor‑specific issue in how ASUS systems populate the MiscData block during status reporting. The July update likely tightened validation logic in WSUS/IIS, so previously tolerated empty fields are now rejected. That matches the WebService.ValidateEventBatch failure you’re seeing.

    At this point, the recommended path is to confirm whether Microsoft has acknowledged this regression in the July 2026 CU. If not, the workaround is to temporarily disable strict validation by rolling back the cumulative update or applying the latest servicing stack/hotfix once released. Another option is to monitor for a vendor BIOS/driver update, since MiscData often includes hardware descriptors that WSUS parses.

    For immediate troubleshooting, you can capture the full client report payload with bitsadmin /list /verbose or by enabling WSUS client logging (%windir%\WindowsUpdate.log on Windows 11 via Get-WindowsUpdateLog). This will show exactly which MiscData field is malformed. If it’s consistently t=, then the ASUS WU client is sending an empty telemetry tag that WSUS now rejects.

    I hope you've found something useful here. If it helps you get more insight into the issue, it's appreciated to accept the answer. Should you have more questions, feel free to leave a message. Have a nice day!

    Domic Vo.

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    10 people found this answer helpful.

  2. Marco 61 Reputation points
    2026-09-09T09:37:19.3+00:00

    Solution: Install kb5122882 2026-09 Comulative Update on wsus server

    Was this answer helpful?

    3 people found this answer helpful.

  3. Veera Badhra Sudha Kishore Naidu Mortha 0 Reputation points Microsoft Employee
    2026-09-30T05:17:59.75+00:00

    I'm troubleshooting similar issue in our WSUS environment and would appreciate any guidance.

    Environment

    • WSUS Server: Windows Server 2016
    • Client Servers: Windows Server 2016 and Windows Server 2019
    • WSUS server and affected clients have the latest September updates installed

    Issue A subset of servers continues to experience reporting issues despite being fully patched. While reviewing logs, I found the following error:

    Plain Text

    Exception occurred while parsing MiscData for event InstanceId: <GUID>.

    Exception: System.ArgumentException:

    Error occurred while parsing MiscData for event.

     

    MiscData element:

    g=<GUID> | <GUID>

    Troubleshooting Performed

    • Verified September updates are installed on the WSUS server.
    • Verified affected Windows Server 2016 and 2019 clients are fully patched.
    • Confirmed WSUS synchronization completed successfully.
    • Forced Windows Update detection and reporting cycles.
    • Reviewed Windows Update and WSUS-related logs.
    • Issue only affects a subset of servers; others are reporting normally.

    Questions

    1. Has anyone encountered this System.ArgumentException related to parsing MiscData events?
    2. Is this a known WSUS or Windows Update issue on Server 2016/2019?
    3. Are there specific logs, hotfixes, or remediation steps that should be investigated?
    4. Could malformed event data in the Windows Event Log cause WSUS reporting failures?

    Any recommendations or similar experiences would be greatly appreciated.I'm troubleshooting an issue in our WSUS environment and would appreciate any guidance.

    Environment

    • WSUS Server: Windows Server 2016
    • Client Servers: Windows Server 2016 and Windows Server 2019
    • WSUS server and affected clients have the latest September updates installed

    Issue A subset of servers continues to experience reporting issues despite being fully patched. While reviewing logs, I found the following error:

    Plain Text

    Exception occurred while parsing MiscData for event InstanceId: <GUID>.

    Exception: System.ArgumentException:

    Error occurred while parsing MiscData for event.

     

    MiscData element:

    g=<GUID> | <GUID>

    Troubleshooting** **Performed

    • Verified September updates are installed on the WSUS server.
    • Verified affected Windows Server 2016 and 2019 clients are fully patched.
    • Confirmed WSUS synchronization completed successfully.
    • Forced Windows Update detection and reporting cycles.
    • Reviewed Windows Update and WSUS-related logs.
    • Issue only affects a subset of servers; others are reporting normally.

    Questions

    1. Has anyone encountered this System.ArgumentException related to parsing MiscData events?
    2. Is this a known WSUS or Windows Update issue on Server 2016/2019?
    3. Are there specific logs, hotfixes, or remediation steps that should be investigated?
    4. Could malformed event data in the Windows Event Log cause WSUS reporting failures?

    Any recommendations or similar experiences would be greatly appreciated.

    Was this answer helpful?

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