I have a file that I can't upload and I get this message. I have seen offers to help fix these files before.. Would someone be able to lend a hand? Thanks!
This should work for you - 2020-12-22-12-24-00-fixed.zip
Unzip the file then import into Garmin Connect using the import data page.
Repaired using Fit File Repair Tool.
Some tips to help minimize the occurrence of corrupt fit files: