I have an EDGE1000. Garmin Express does not upload activities and gives me the message that the activity files are corrupted. I have no problems uploading the files manually to Strava, so there cannot be a problem with the files.
Have you attempted to upload them manually? If not, please follow the instructions in the link below:
How do I manually upload data from USB Mass Storage devices to Garmin Connect?
If they upload manually, please ensure that Express is up to date.
