I have a report which uses .tsv files as input.
Automatic actualisation worked fine for a long time, then something got messed up and it failed one time.
I have already fixed the underlying mess, and can refresh just fine via the both the refresh botton in the browser and also in pbi desktop. However, I cannot reactivate the automatic scheduling as it is greyed out.
It may want to have some type of credentials, but there are no credentials neccessary for it.
What operations you do before broken the refresh ? Any changes enabled on datasource or credentials?
Please provide more detail informations to help us clarify your scenario.