You can reopen a closed alert from the Alerts page or when viewing the details of the alert.
To reopen an alert from the Alerts page:
From the main menu, select Investigate > Alerts.
To reopen a closed alert, right-click the alert row in the table and select Reopen from the pop-up menu.
Alternatively, you can click
at the end of the row and select Reopen.
To reopen an alert from the details page:
From the main menu, select Investigate > Alerts.
Click on a closed alert in the alerts list to display the alert details.
Select Reopen from the menu in the upper right corner of the alert details page.