Error in May 2020 release of Power BI for RS: 'An item with the same key has already been added.'

[chrpus]

Hi,

since upgrading to the latest version of Power BI Desktop for Report Server I am encountering a problem when trying to refresh one of my reports. The error reads

"OLE DB or ODBC error: [DataSource.Error] An error happened while reading data from the provider: 'An item with the same key has already been added.'."

I did not receive this error in the previous version and it is also not present in the normal Power BI Desktop app.

Any advice on how to approach this would be much appreciated. Until this is resolved I am not able to make changes to published versions of this report.

Thank you on beforehand!