Power Query - Import Error Help

I'm brand new to Power Query (day #1 to be exact), and having trouble importing my data. I'm currently in an Excel .xlsm workbook which i am buiding to be able to print daily stats for a business based. These stats will be aggregated from the company's daily reporting (which is also in .xlsm format).

To start, I opened a blank new sheet in my workbook, then went to Data>Get Data>From File>From Folder. Then when the file explorer appeared, I navigated to & selected Desktop>YTD Reports because that folder will house all 6 of my daily data folders which I will extract data from. There is currently only 1 file in this folder, but that's because I'm just trying to get it running correctly before I load up the other files.

However, then after selecting COMBINE & TRANSFORM DATA, I receive this error even though the file is a valid Excel Doc (.xlsm):
Error.PNG
ANy idea why this is happening, and how I can get past it?