Missing product_ids in worksheet 'Specials' Error

Hi,
I am new to Opencart. Trying to import product from Excel file and get this error. Do I need to put data in 'Special' tab or my setting have problem?

Export/Import: Missing product_ids in worksheet 'Specials'!
Export/Import: Missing customer_groups in worksheet 'Specials'!

Thanks for any help.

There is no need to put data in 'Special' tab, you can keep it blank. You can keep all column values blank. But if you enter data in other columns & keep Product id column blank you will get Error Missing product_ids in worksheet 'Specials'!