New-MgSchemaExtension でエラー（Your organization must own the namespace customdomainA as a part of one of the verified domains.）

powershellでも Graph Exploror でも同様の結果です。

schemaExtensionの作成を行いたいのですが、何をしてもエラーになります。

カスタムドメインは検証済みで、命名規則も問題ないと思います。

New-MgSchemaExtension : Your organization must own the namespace innovax as a part of one of the verified domains.

Status: 400 (BadRequest)

ErrorCode: BadRequest

Date: 2025-08-13T13:17:22

Headers:

Transfer-Encoding : chunked

Vary : Accept-Encoding

Strict-Transport-Security : max-age=31536000

request-id : dc967d7d-d956-4d9d-99fa-439ab86bf4ae

client-request-id : b4a79fe6-ef16-4ca7-8cb3-56fa92cfb679

x-ms-ags-diagnostic : {"ServerInfo":{"DataCenter":"Japan East","Slice":"E","Ring":"5","ScaleUnit":"002","Role

Instance":"TY2PEPF00005FC4"}}

x-ms-resource-unit : 1

Cache-Control : no-cache

Date : Wed, 13 Aug 2025 13:17:21 GMT

発生場所 行:14 文字:1

• New-MgSchemaExtension -BodyParameter $params

• 
      + CategoryInfo          : InvalidOperation: ({ Headers = , b...hemaExtension }:<>f__AnonymousType4`2) [New-MgSchem
  
     aExtension_Create]、Exception
  
      + FullyQualifiedErrorId : BadRequest,Microsoft.Graph.PowerShell.Cmdlets.NewMgSchemaExtension_Create
  
  

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Connect-MgGraph -Scopes "User.ReadWrite.All", "Directory.ReadWrite.All","Directory.AccessAsUser.All","Application.ReadWrite.All"

$params = @{

Id = "customdomainA_affiliations"

Description = "ユーザーの兼務・出向情報を格納"

TargetTypes = @("User") 

Properties = @(

    @{Name="affiliations"; Type="String"} 

)

Status = "InDevelopment"

}

New-MgSchemaExtension -BodyParameter $params