I'm getting the same message for a few days now (UK). It briefly worked on Firefox but that's gone the same way as the other browsers (Opera, IE, Chrome). Nothing to do with clearing cache. It's very annoying as I need a TCX file but there's no way to save them using the android app version (which still works) as it's very basic.
I have spoken to the support team and they have taken the details this afternoon. After going out to walk the dog (too much information) I return to find if I use my mac and use firefox I can log in to my own and my wife's Garmin connect account as normal.If i then try safari i get the limited screen(menu,notifications,queue etc). What confuses me even more is that if I use my wife's mac account, in both firefox and safari, to log in to Garmin accounts neither work. I'm not sure if this information will help anybody work out what has happened but thought I would share it.
