Thanks for reaching out to us, victorb17. This icon would indeed usually be an indication that either there is no footage at that time or there is something wrong with the video (incomplete file upload or corrupted file). If you are able to manually navigate to this time and view the footage, then this would indeed be an issue. Please email us at firstname.lastname@example.org with screenshots of your error icon and also your ability to view the footage properly at the respective time.
Look forward to hearing back from you.