Hi Deepak,
In TBEXN, do not select any file in the upload file area . Click on create button. Excel will open and you will receive the pop-up to enable macros. Click Enable. The output will show the existing prices or it might even show a blank worksheet. Click save. Save this file on your computer and then add your data to this file and then use the new file to follow the usual process to upload. Also in your file, check the date format if its correct.
You shouldn't get the error again.
Regards,
Nikhil