Import Tickets problem

Hi,
I'm trying to import tickets from a csv file generated on Salesforce, but even though all the mapped fields have data, I'm getting this error:

(Reason: Due to empty values for any of the mandatory fields)

What can be the problem?
Please, see attached file with the record that I'm trying to import. I changed the extension of the file, because I couldn't attach it as a .csv file.

Thanks,

Hernan