What did you do to cause this? Opened new Ticket, created an attachment.
What page were you on? Ticket page (the page that is displayed when you click on some Ticket). The Ticket must have attachment to it.
Describe the defect: The text "added by {1} {2} ago." next to the attachment download link is nowhere to be found in the translation file and cannot be translated.
added blank attachment, so the untranslatable text could be visible right now, on this page