What can potentially cause errors when you upload a Microsoft excel file into an SAP Ariba Sourcing event?

You are creating event content in Microsoft excel.

What can potentially cause errors when you upload a Microsoft excel file into an SAP Ariba Sourcing event? Note: there are 3 correct answers to this question.
A . Adding new rows
B. Editing the column headers
C. Sorting and filtering the excel file
D. Creating a system ID for new rows
E. Editing the tab labels

Answer: C,D,E