Data Import Wizard not letting null values for IDs

Summary

Missing required value for field 'c_id'

Content

Hi,

I am trying to do an import and I had a question around pasing null values for IDs as I'm getting an error. I try to import custom object data but I have created a simple example for contacts to demonstrate the problem.

I have a CSV file of contacts to import and I was hoping it would work that if I pass contact id it will update records and if I leave the field blank it will create new contact with the incremented c_id but I get an error: "Missing required value for field 'c_id'"