Import file keeps skipping on Row 17

I’m testing this plugin with my member list, prior to launching my client’s new website. I’m using a test file which consists of 20 rows of data.

Each time I run an import, I get the following error message: “Row number 17 does not have the same columns than the header, we are going to skip”

I have made sure that all other rows and columns are clear. I have deleted row 17 and tried again. I have switched the content of the rows around so that the content of row 17 is different. Nothing fixes the problem, and each time the import stops at row 16 and doesn’t import the rest of the rows.

My real data file is 258 rows – please don’t tell me I’m going to have to break it into 16-row chunks to get all my data imported ??

Hope you can help. I have screenshots etc if you need them. Thanks heaps.