@Kien_NDM , Apologies for the delay in response. This is a known issue, and the only way you will be able to get this deleted is to contact Azure Support. If you do not have a support plan, please Email me at with your subscription ID and a link to this post, and I will enable a one-time free support request for you to get the subnet deleted.
Workaround:
- Create App Service Plan with the same name as the deleted one
- Create App Service with the same name as the deleted one
- Link App Service with the VNET subnet
- Disconnect VNet from App Service -> Networking -> VNet integration -> Disconnect
- Delete subnet
Reason for this Error:
The new VNET integration feature (Regional Vnet Integration) must set locks on subnets in the Network Resource Provider, we set these locks by putting a structure called a Service Association Link onto the Subnet, which is a privileged operation that only Microsoft.Web and some other internal Azure services have access to, this ends up being odd cases where these locks don't get cleaned up. The result is that the customer will have a subnet that cannot be deleted or used because a Service Association Link still exists on the subnet.
Azure App Service and Azure Networking Product Group keep working on to fix the issue completely.
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