Based on the error message, it looks like it's a cloud backup plan. Are you sure the storage destination is local storage? I'd advise you to send logs to our tech support team so that they can verify your backup plan configuration and advise on the best solution.
Hi all! We have reproduced the issue on our end and will address it in one of the upcoming updates. As a solution, please consider using the New Backup Format instead of the Legacy Backup Format. We apologize for any inconvenience!