Garmin Express says there is a software update available for my 310XT. When I click to install it, it tries to install and then just says there was an error. Meanwhile, it won't Sync data. I did a Master Reset last week because I always seem to have to do one after the time change, so I don't think there is a ton of data out there. I'd rather NOT Master Reset again.
*Update*
I got this working by deleting my activities and powering the device off and on.