unable to add a new domain.

I think only layer u can reset is Settings → Domains → clear any pending / failed → try add again… same drop means the fault lives inside the tenant, and only Support can clear that state.

Hi Marina Denton

Based on your description, I understand that you’re unable to add a new domain in Microsoft 365 and are receiving an error when selecting “Add domain.” 

For guidance on how to add a domain, you can refer to the official Microsoft documentation: Add a custom domain to Microsoft 365 - Microsoft 365 admin | Microsoft Learn 

Since you are encountering the error immediately after selecting “Add domain,” you may want to try the following: 

• Open the Microsoft 365 admin center in an InPrivate/Incognito window or use a different browser  
• Clear your browser cache and cookies  
• Try again after some time in case this is a temporary service issue  

If the issue persists after these steps, I recommend raising a support ticket with the Microsoft Support team for further investigation. 

For further instructions, please follow this guide: Get support - Microsoft 365 admin | Microsoft Learn. 

Please understand that this is a public peer-to-peer community forum. While moderators and community members can share guidance and experiences, we do not have access to tenant-level details or backend systems. 

Best regards,

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