If the software brought you to this page, it would appear that there's an issue with the Excel file you are trying to import. This could be from drop-down headers on the Excel file, or from having many tabs of spreadsheets on the file.
Next steps:
1. Open the Excel file in Excel.
2. Create a new/blank Excel file
3. Copy and Paste the contents into the new/blank file (and save).
Import using the newly created file.
Then, import the new file into Treasury Software.
If you are still unable to import the file, you have the option of copying/pasting the data in. Open up the Excel columns so all numbers show (no fields should show exponential notation), then copy/paste the fields with data, rather than selecting a file.