Beware : The new Garmin Express Update deletes your Garmin ANT+ Agent. There is a pop-up box that tells you this. However, if you normally blindly click 'yes' without reading the warnings then the next time you plug in your USB stick to sync your 910XT it will not work. It took me 2 days to figure this one out.
Do not worry. Just down load and run the Garmin Express update. Then search 'Garmin ANT+ Agent'. Re-down load the ANT+ Agent and you are back where where you started in less than 60 sec.
After the first upload "from file" transfer to Strava let's say... (C:\ProgramData\Garmin\GarminConnect\Forerunner 910XT-3841823198\Upload\FIT_TYPE_4) the next time once you hit Browse, all my FIT files are there. The last one is the most recent. Originally I was disappointed, but now its better...quicker.
I had the same issue. I re-downloaded the ANT+ Agent, all went well, but I can't upload my files from my 910XT to Training Peaks anymore like I always did in the past.
Yeah, this irritated me as well. I only used the Garmin Express to download the latest firmware update but I didn't know I lost the ability to download files directly to my laptop so that I could then upload to trainingpeaks. You can export files in Garmin Connect to your computer and then upload to TP. So, you're saying if you repeat the download of Garmin Express there is a way to re-enable the ability to download files from your 910 directly to your computer again?