Strava changed their authentication methods in October 2019. It is possilbe that you will need to re-connect your account to Strava. If you are having trouble, try and delete the cookies for the gotoes.org website. That way, you will be forced to reconnect to Strava - and your browser will receive a new log in key. Here is an image of how to do that:
From the upload page, you can reset GOTOES | StravaTools Cookies by clicking the "Reset" link seen at the bottom of this table:
From the 2nd page where you set the parameters, you can reset GOTOES | StravaTools Cookies by clicking the "Reset" link seen in the "Sending Files to Other Apps" tab:
