I cannot repro the same issue using latest Aug 2017 version of Power BI Desktop on my side. Please try to clear the permissions related to this SharePoint source as following screenshot, and then try with another link like https://***.sharepoint.com (without Operations here) to see if it works.
If issues still persists, I suggest you to collect fidder traces and create a support ticket at http://support.powerbi.com (see bottom of page).