@Asphalt DR​ :

It seems like the credentials you provided for the external location in the Unity Catalog are not sufficient to read the files from the configured path. Here are some steps you can take to resolve the issue:

1. Double-check that the MI has the correct permissions. Ensure that the MI has the necessary permissions to access the external location, including read access to the files in the configured path.
2. Verify that the external location is correctly configured in the Unity Catalog. Make sure that the credentials provided in the Unity Catalog are correct and up-to-date.
3. Check if there are any firewall or network settings that could be preventing access to the external location. Ensure that the network settings are properly configured to allow access to the external location.
4. Verify that the access connector is properly configured in the storage account. Ensure that the access connector has the necessary permissions to access the external location.