ERROR 2027 (HY000): Malformed packet (1 reply)

Hi folks,
i have a issue with MySQL Workbanch 6.3.6, in connection get the error:
ERROR 2027 (HY000): Malformed packet
Both using client or using command line.

For company's policy I must use MySQL Workbanch, but i have tested connection with HeidiSQL_9.4_Portable, it's works.
Hints?

Thanks