Unlike Google Drive, Mega doesn’t show a "File not found" error until you click the link. If you manage a lot of links, you can use third-party link checkers (though be cautious with untrustworthy sites). A dead link usually returns: "The file you are trying to download is no longer available."
Data is protected both while being uploaded and while stored on MEGA’s servers. Safety Risks: mega link files
This includes the decryption key. Anyone with the link can download the file. Unlike Google Drive, Mega doesn’t show a "File