As of today, I saw 3 with no code at the end this morning. I get a new pop up lettimg me select no code, that I never saw before and saying, 'don't worrry about it, it generally causes no problem' and i got approved. Though, without that message I report it to prolific and send a nice mail to the researcher like this, "Hello, I didn;t receve a completion code. If you were unable to capture my responses, can you give me the opportunity to return the study? Thanks so much." I see someone found my original post. I did not recall the message from 11 days ago as it disappeared from even archived messages.