If you do not have any other Domain Services Instance deployed by any other user but you are getting this error then you need to check for the resources - NSG and VMs attached to the AADDS if these are deleted as well. You can also review the below :
- Domain controllers for the managed domain are de-provisioned and removed from the virtual network.
- Data on the managed domain is deleted permanently. This includes custom OUs, GPOs, custom DNS records, service principals, GMSAs etc. that you have created on the managed domain.
- Machines joined to the managed domain lose their trust relationship with the domain and need to be disjoined from the domain.
- You cannot sign in to these machines using corporate AD credentials. Use the local administrator credentials for the machine, instead. Deleting the managed domain does not delete your Azure AD directory or otherwise adversely impact the directory. See this link for further clarification
Also, your tenant can have several subscriptions but allowed to have an unique Azure ADDS. So, you need to make sure that no instance has been deployed from any other subscription to the same tenant.
Can you please check if you are seeing domains using the Get-MsolDomain Powershell cmdlet. You can also check in Azure portal for existing domain services.
Are you having a GA access ? You need to have Global Administrator access in your tenant for enabling ADS. Also, you need contributor privileges in your azure subscription to mange the Azure ADDS resources.
@Justin Petty Are you still having this issue ?