I know this is an "old" message but I'm having this very same issue and figured I could use the same thread. I am also new to Power BI, I have a report built using Power BI Desktop and I'm getting the data from an Excel file (.xlsx).
Everything was working great until I updated the Excel file with the data, the file is the same (same name and location in my computer), I just updated the existing information and added more information to it.
After doing that, I saved and closed the Excel file, then I went to the PowerBI Desktop and clicked the "Refresh" icon on top (white sheet with green circling arrows), it said it was getting the data from the file (showing the name and progress) and when it was done apparently with no errors, I verified to ensure all the new information was there in the data tab and it is but all the visuals are blank; they have the right fields and everything as before refreshing but they won't show anything now.
Am I doing something wrong?
Thanks in advance!