This is usually just a spam reply and rarely fixes it.

Try opening the 123 file with LibreOffice since it's free and supports opening that file.
https://ask.libreoffice.org/en/question/56118/will-libreoffice-open-lotus-123-spreadsheet-files/ and other replies tell us it can import.

Remember PCs were not that good when we have one last copy. Being such a seasoned user, it's surprising they haven't run into this before and learned to make a backup copy.

-> PS. This thread will be a link free zone to stop the spam.