Is the computer seeing your Forerunner 305 correctly? Does Express detect your device and do you have the option to sync? I understand that its failing I would like to determine at what point it is failing. Do you hit the sync button it looks for your device start to up load download the data to the computer and then it attempts to upload that data to connect and that is where it fails? Please provide some more information on your issue.
What version of Express are you running the latest version is 3.2.19?
What version of firmware is on your device?
What OS are you running? Reason for this is depend on what OS you are using this will determine where the files are stored on your computer prior to the file successfully uploading into Garmin Connect. See FAQ: Where do my activities go on the computer before they are uploaded to Garmin Connect?
I was having the same problem... just would not sync!! It turns out that I also had sync manager installed for HTC phone. I removed that and it connects no problem now.
