Solved
External table is not in the expected format.. Was working before, now it's not.
I'm trying to look at two .iif files for comparison of their data. The following lines of code are throwing an error for me: 'Get the two files we need. We will use the original file to verify ...
I had faced similar issues with Excel 2013 files. One workaround I found is to open the file before running any reading commands.
