I'm using the web Power BI.
Dataset is connected to an Excel file on OneDrive.
The excel file is automatically updated through Microsoft Flow.
After a few days of the system working without a problem, I started to get a Dataset refresh error: "An unknown error has occurred".
I will appreciate your help
Thats not much to go on. I'd recommend downloading Power BI Desktop and attempt to open the file from there first. My expectation is that something in your file has changed. This could be a column header name, number of junk header rows that need to be removed, or something like that.
Also check things like: "Has your password changed?"