If APP can't find any data from your device,pls try the following tips to troubleshoot the problem:
1. Restart the device and upload again , in case the activities hadn't been successfully saved in the device.
2. Delete some of the history fit files and try again .It may happen when there are too many files inside the device, as APP can only recognize limited files.
What's fit file? Where is it?
1) Power off the device, connect it to computer.
2) Short press left button,the device will be recognized as a new disk.
3) The fit file in the activities file is the cycling data.
If it still can't be transfered, pls try to provide us the exact fit file for further analysis.
The procedure is used to solve the problem: There is activity inside my device, but APP can't not find the activity .