Azure Container Apps: Internal Server Error on provisioning ACA Environment in existing VNet

Product:

Azure Container Apps, Azure Virtual Networks

Problem:

As I was trying to set up ACA in an existing lab VNet, I discovered that some of my operations for creating the ACA Environment were failing with "Internal Server" error. 

Fortunately I've been through this type of obtuse error messaging from Azure before, so I was able to quickly walk back to what seemed to be causing my issue. 

Powershell received the following error:

New-AzContainerAppManagedEnv @EnvArgs
New-AzContainerAppManagedEnv : Internal server error occurred.  correlation ID: <snip>
At line:1 char:1
+ New-AzContainerAppManagedEnv @EnvArgs
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: ({ SubscriptionI...    }
  }
} }:<>f__AnonymousType16`4) [New-AzContainer..._CreateExpanded], Exception
    + FullyQualifiedErrorId : InternalServerError,Microsoft.Azure.PowerShell.Cmdlets.App.Cmdlets.NewAzContainerAppManagedEnv_CreateExp
   anded

ARM deployments received multiple of the following error and then timed out: 

    "properties": {

        "statusCode": "InternalServerError",

        "serviceRequestId": null,

        "statusMessage": "{\"error\":{\"code\":\"InternalServerError\",\"message\":\"Internal server error occurred. correlation ID: <snip>\"}}",

        "eventCategory": "Administrative",

        "entity": "/subscriptions/<snip>/resourcegroups/<rgname>/providers/Microsoft.App/managedEnvironments/<envname>",

        "message": "Microsoft.App/managedEnvironments/write",

    },

 

 

Solution: 

Remove IPv6 address spaces from the VNet. 

 

HTH.