Failed data refresh and option to edit credentials completely blank

Hi hopefully someone can help me here,

Im using the personal gateway to refresh folders of csv files. Previously(yesterday) the refresh worked fine manually, however I had the scheduled refresh set for today at 10am and firstly the refresh failed stating the credentials were missing from the cloud. Secondly when going to edit credentials there is no option to edit the credentials any more, when I click on"Data source credentials" there is nothing in the drop down. Have I missed a step here or will this just not work in this way?

Thanks for your help