This is a known quirk with the UI validation for ACI worker pools. Even though you've specified values for the registry URL and identity, there's an additional step required to properly configure the ACR authentication. Here's how to fix it: 1. In the work pool configuration, you need to explicitly set

job_configuration.registry.identity_type

to

"managed"

in addition to providing the registry URL and identity. 2. The complete configuration should look something like this:

yaml
job_configuration:
  registry:
    url: "<http://your-registry-url.azurecr.io|your-registry-url.azurecr.io>"
    identity: "your-managed-identity"
    identity_type: "managed"

If you're using the UI: 1. Create the ACI work pool 2. Under "Job Configuration", expand the "Registry" section 3. Set the following: - Registry URL: your ACR URL - Identity: your managed identity - Identity Type: Select "Managed" from the dropdown The UI validation should resolve once all these fields are properly set. If you're still seeing the error after setting all these fields, try refreshing the page, as sometimes the UI validation state can get stuck. For more details about ACI worker configuration, you can refer to the official documentation. Would you like me to provide more specific details about any part of this configuration?

I see the issue now - there's an active bug with the UI validation for ACI worker pools (issue #10465). The UI is incorrectly showing the fields as required even after values are entered. Here's what you can do to work around this: 1. If you're using the UI: - Enter your Registry URL and Identity values as you've been doing - Despite the UI showing the error messages, try clicking "Next" anyway - in many cases it will proceed despite the validation messages - If the "Next" button remains disabled, you'll need to use the alternative approach below 2. Alternative approach - Create via API/CLI:

bash
   prefect work-pool create \
     --type azure-container-instance \
     "my-aci-pool" \
     --image-registry-type "acr-managed-identity" \
     --image-registry-url "<http://your-registry.azurecr.io|your-registry.azurecr.io>" \
     --image-registry-identity "your-managed-identity"

This is a known UI bug that's being tracked. The validation is overly aggressive and shows the fields as required even when they've been properly filled. The underlying functionality should still work correctly once the work pool is created. Would you like me to provide more details about any of these approaches?