Ok,
Basically this is a resume.
If put empty values in everything dont create -> give an error
If put some values nulls -> give error but in SQL Server create with a empty cell
If put all values correct -> give error but in SQL Server works fine
If put all values in text and in entity atributes too -> give error but in SQL Server works fine
Error given all the time excepts when i dont put an excel file or its a file completely empty. -> "Specified cast is not valid "