Hi,
this is due to your excel version, not due to CB or BF
But you can open it on this way.
1) open your excel
2) go to file -> open -> browse->find your excel file
3) select your excel file-> next to the Open you will see narrow, click on this narrow and select Open and repair
4) click on Repair and that is it
You will see your exported records
Regards,
Tihana