Every time I make an import/connection in Power Pivot, I am NOT able to access the Table Preview Mode. Which means that I am not able to add new columns from data source or change my selection. Only Query Design Mode are available. (I have not made any changes in the query editor, just made any connection). It does not matter if I make import from Excel file, text fil or data base. It happens all the time. This have been the case for the last month. The only thing I added on my computer since then is Power BI Desktop. Please help!