That's a terrible message for people trying to run other people's code, unfortunately. It wouod be more useful to say "Are you trying to run Python 2 code in Python 3?", If Python detects enough "2isms" in the file.
Except that is imprecise and can be misleading. It is certain you called print incorrectly. It is not known if you just made a mistake or are trying to execute python 2 code.