Regarding Error CertificateServiceClient-CertEnroll Event id 87

Joel Craycroft001 65 Reputation points
2026-08-08T22:44:21.73+00:00

Every Single TIme That I boot up Windows 11 25h2 Pro OS with all Windows Updates Applied to a point at least I get this error message after applying the latest and greatest Windows 11 Updates under the event viewer under administrative events : SCEP Certificate enrollment for Local system via [PII Removed] failed:

PkiStatus(11): SCEPDispositionPendingChallenge

EnrollStatus(32): EnrollUnknown

The operation completed successfully. 0x0 (WIN32: 0)

SubmitDone

SubmitV2Attestation: Bad Request

{"Message":"V2 Protocol AIK certificate requests with P-256 ECC public keys are not supported. Public key algorithm: [PII Removed], Key length: 256."}

HTTP/1.1 400 Bad Request

Date: [PII Removed]

Content-Length: 154

Content-Type: application/json; charset=utf-8

X-Content-Type-Options: nosniff

Strict-Transport-Security: max-age=31536000;includeSubDomains

x-ms-request-id: [PII Removed]

[PII Removed]

Windows for home | Windows 11 | Windows update
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Alex-L 12,565 Reputation points Microsoft External Staff Moderator
2026-08-10T13:56:35.02+00:00

This is a public forum, please refrain from posting any personal information or if you do, please blur them out for your safety and privacy.

Hi Joel Craycroft001

This Event ID 87 is typically related to TPM AIK (Attestation Identity Key) certificate enrollment, not Windows corruption. The error indicates Microsoft's attestation service rejected a P-256 ECC key request during enrollment.

If your TPM shows "Ready for use", and Windows Hello, BitLocker, and other security features work normally, this is generally considered a benign event that does not affect normal system operation.

Ensure your BIOS, chipset/AMD TPM firmware, and Windows updates are current, then monitor future updates from Microsoft and your device manufacturer.

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  1. Leon 0 Reputation points
    2026-08-11T18:20:07.7666667+00:00

    so will windows fix it soon or do i have to do anythink ?

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