Ok, I resolve it with this post
The difference that I apply was that, instead of dumping with option utf8mb4 it was latin1.
For the DB backup
mysqldump -uusername -ppassword -c -e --default-character-set=latin1 --single-transaction --skip-set-charset --add-drop-database -B dbname > dump.sql
The rest was like the post in the link. It works for the upgrade from 2.4.8-4 to 3.0.2
Thanks,