If this popup keeps appearing, you can select Block and check the box to Remember action for this certificate. Otherwise, this same message will reappear if you go to the website again.

A typical reason that this message will pop up is because ESET believes it has identified an untrusted certificate from the webpage that you are browsing. This could be a legitimate problem, but it possibly could also be caused by other factors such as an incorrect system date on your PC. In some instances, you might research this and believe that that there is no problem with the particular page you are visiting. This feature allows you the opportunity to make an informed decision to avoid potential problems. If you are certain that there is in fact no problem coming from the page, you could also choose to allow the traffic to proceed, but do this only after informed research.