data refresh issue - unsupported data source

I've read the existing posts on this but are of no help...

I have an excel file of 3..4MB as  my data source, loaded into powerbi.com

I created several reports and a dashboard off of it

upon trying to refresh the data source manually, i get the triangle error and this message which I'd love if someone  could offer some actually helpful solution...I've recreated the dashboard several times at this point and hugely irritated at this experience /inability to refresh.