Getting nullReferenceException when importing Products from Excel file.

When I try to import products from an Excel file (.xlsx) I get a nullReferenceException.

After debugging I took the screenshot below. How can I fix this issue?

Click here for screenshot.

Hi,

Is it possible to share your Excel file?

I managed to import the Excel file successfully so this issue is solved.

Problem:
I was working with an .xls file and converted it to xlsx. Tried to upload it.

Solution:
I just exported a new xlsx and started from my store, finally uploaded this xlsx file.

Thank you Andrei