Advocate II
No sense anymore in downgrading Power BI Desktop, as the published version will now also crash on the Power BI Server ("We couldn't parse the input provided as a DateTimeZone value").
As a workaround, I added a line to power query [xxx = Table.ReplaceErrorValues(xxx, {{"Date modified", null}}),] and added the [try ... otherwise null] to logic depending on [Date Modified] (I needed to shift the datetime to UMT since I got Californian time) to still get through the scheduled refresh, accepting that the fact this field really is meaningless. Also sorting on the [Date Modified] field is useless now...
Is it that difficult that the Sharepoint.Files() function returns a true datetimezone field for [Date Modified], rather than a text field (up to last February 2018 release) using the sharepoint settings (localization and timezone)?