Dear @Lu Gan,
Thank you for posting your question in the Microsoft Q&A forum.
Based on your description, could you please provide more information as whether you know when the tenant was last active?
Because the error message you encountered indicates that your tenant has been inactive for over 200 days past the billing cycle, triggering Microsoft’s effort to remove inactive tenants. When a tenant remains inactive for this period, the OMS commerce system imposes a login block (AADSTS5000225). Twenty days after the login block is applied, the tenant is permanently deleted.
Please prefer to this article for more detail information Tenant inaccessible due to inactivity
In this situation, I recommend you contact to Microsoft Support team and provide detail information of your issue so they can help you resolve this issue.
The Microsoft Online Support Team has higher permission than us moderators to remotely assist you and collect background logs for the root cause. This is a more efficient and direct way in recovering this scenario for you
If you are user, you can contact to your IT/administrator. They can follow these steps as the link: Get support - Microsoft 365 admin.
And if you're unsure who your Global Admin is, this guide may help How do I find my Microsoft 365 admin? - Microsoft Support
If you are an Admin, you can use this link to find the appropriate contact number: Global Customer Service phone numbers - Microsoft Support
Note: Please understand that as forum moderator, my primary goal is to provide helpful guidance and support through general troubleshooting steps. While I don’t have access to internal systems or test devices required to resolve backend issues, I truly appreciate your understanding of these limitations. I genuinely hope the information I share helps guide you in the right direction, and I'm always here to assist as much as I can within my scope.
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