I have a Garmin Forerunner 10 from 2013. After not using it for a few years, I've been using it regularly this year. It needs to be charged before each run or the battery will die. Every few weeks, when I plug it in to my computer to transfer my run data, something happens and the .FIT files become corrupted or completely disappear. I currently have two .FIT files that can not be synced. The error message states "unsupported file type." I tried to open them with GPXSee, but it returns the error "Error loading data file. Premature end of data." When I look at these two activities on my watch, the summary is still there, but the time for each mile is gone.
Is there anything I can do to try and fix or view the data in the .FIT file? Or anyone who can help me try to salvage the data? Is this watch just too old to be reliable anymore?