Ballu, there is another reason this error can occur. B&Me version in your car could be 5.4.09, which was loaded into all Linea/Puntos. If you directly try to upgrade to 5.5, you will get an error. The version has to be upgraded to 188.8.131.52 first and then only 5.5 will be accepted. I don't know if you tired this, but I feel this could be the problem.