Why this alert is displayed:
Validation is an operation that checks the possibility of data recovery from a backup. You have specified this option in a backup plan or created a separate validation plan, and this operation failed. The alert drives your attention to this issue, because successful validation ensures that your backup will be restorable and a missed validation might put your data protection plan at risk.
When the alert is deactivated:
This alert is deactivated once validation is started again.
How to troubleshoot this issue:
Check the log of the faulty operation: click the machine to select it, click Activities, and then find the warning in the log. The message should point you to the root cause of the issue the software notifies you about.