Microsoft Support Assistant returns HTTP 500 for non-ASCII account names

Timofey Denisov 0 Reputation points
2026-10-07T11:42:59.67+00:00

Microsoft Support Assistant on support.microsoft.com has a reproducible server-side failure when the authenticated Microsoft account profile contains non-ASCII characters in the user's name.

Reproduction

  1. Open https://support.microsoft.com/en-us/home/contact
  2. Enter: Gaming Services GameInput MSI detection defect
  3. Select Get Help
  4. Select Ask our Support Assistant
  5. Send the request.

The Support Assistant Stream request returns:

HTTP 500
{"error":"Request headers must contain only ASCII characters."}

The browser-side HTTP request headers contain only ASCII characters, so the error does not appear to originate from a malformed header sent by the browser.

A/B test

With a Microsoft account profile containing non-ASCII characters in the name, the Support Assistant request fails with HTTP 500.

After changing the same account profile name to ASCII-only characters, the same Support Assistant workflow completes normally and the HTTP 500 error disappears.

This provides a reproducible A/B test:

Non-ASCII account name → HTTP 500
ASCII-only account name → no HTTP 500

The browser used for testing was Firefox 157.0 on Windows 11 Enterprise 25H2 x64.

The browser-side HAR also contains correlation IDs for the failed requests:

3b5e8862-81d1-4797-8f7b-8a05ffcc2b89
9829ec10-4d5a-4687-9ad9-ce2ea4c8b7db

I previously contacted Microsoft Consumer Support about this issue. The support case was acknowledged as appearing to be a backend issue in the Support Assistant service, but the case was closed without an engineering escalation.

I was then directed to Microsoft Tech Community. My technical report there was automatically rejected as SPAM by the Community system.

Question

What is the correct official Microsoft channel or product team for reporting a reproducible defect in the public support.microsoft.com Support Assistant / CMSP backend?

I am specifically looking for a route to the engineering/service team responsible for this component, rather than troubleshooting Windows, Firefox, or the Microsoft account.

I have a sanitized HAR and additional technical evidence available for private submission if required.

Windows for home | Windows 11 | Apps
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  1. AI answer

    2026-10-07T11:43:22.0933333+00:00

    Use Microsoft Support, not Tech Community, as the official route for a defect in the public support experience.

    For a consumer-facing support.microsoft.com issue, the supported path is:

    1. Open Get Help on the web.
    2. Describe the issue as a support site / Support Assistant backend defect.
    3. Request chat with support if self-help does not resolve it.
    4. Provide the sanitized HAR and the correlation IDs in the case.

    Relevant facts from Microsoft’s support guidance:

    • Microsoft says technical support requests for Windows, Office, account, and billing issues should start through Get Help, which can provide self-help or connect to the most appropriate support channel, including chat.
    • Microsoft account support agents are not allowed to directly change account details or send password reset links, so this should be framed as a service defect in Support Assistant, not as an account recovery request.
    • If the issue needs deeper investigation, Microsoft documentation for support scenarios includes sharing copied error details and network traces such as HAR or Fiddler .saz files.
    • If a support request cannot be opened through a portal, Microsoft lists Microsoft Q&A as a public technical question option, but that is not the engineering escalation channel.

    For the evidence package, include:

    • Exact repro steps
    • A/B result: non-ASCII profile name fails, ASCII-only succeeds
    • Browser and OS version
    • Correlation IDs
    • Sanitized HAR
    • Clear statement that the browser request headers are ASCII-only and the failure appears server-side in the Support Assistant/CMSP flow

    There is no separate public engineering intake for this specific support.microsoft.com Support Assistant backend in the provided material. The official route shown is to open the case through Get Help and attach the diagnostic evidence so support can route it internally.

    AI-generated content may be incorrect. Read our transparency notes for more information.

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