Last_IO_Errno: 1236 Cluster DataBase does not synchronize

[BrainyForge]

Hello to all
I ran the guide http://www.howtoforge.com/installing...th-ispconfig-3 ,
for several mesei worked beautifully, probably after the update, the mysql slave server is not updated anymore, I tried to follow the steps in sicronizzazione of the two servers, but I always get the following error

SHOW SLAVE STATUS \ G;

Slave_IO_Running: No
             Slave_SQL_Running: Yes
Last_IO_Errno: 1236
Last_IO_Error: Got fatal error 1236 from master fe When reading data in binary log index file '

What do you advise me to do?

Thank you for your attention