How are you trying to upload the ride to Connect? Wi-Fi? Bluetooth via your phone? Garmin Express on a computer? Have you tried manually uploading the ride by plugging the unit into a computer, going to the Connect website, and selecting the ride log file on the unit?
How many files do you have in the activities folder on your 530? If there is something close to 200 files in there things go wonky so delete/remove most of them.
