Windows and Security Issues
Security changes that might affect the reading of the CSV, Text file
Reboot your Windows OS
CSV, Text File issues
Column Headers should not have any leading spaces in the column name.
SQL does not recognize leading spaces and will reject that column.
Incorrect path, or moved file
The tables and/or their columns inside of the Excel file are not exactly the same as originally mapped.
Bad data in file (ex.: invalid characters, or characters on columns with mostly numbers).