Beginning a few days ago, Garmin Connect (web) stopped its ability to import file data (neither .tcx nor .fit activities). Automatic Wi-Fi and cellular data uploads still work, but manual file imports do not. This is a recent bug and I've read other complaints on forums. I'm using the latest Microsoft Edge Browser. Suggestions to try other browsers are ridiculous. Just fix your bug and notify users when the problem has been resolved. Thank you.