Increase max_allowed_packet

max_allowed_packet is set in mysql config, not on php side

[mysqld]
max_allowed_packet=16M 

You can see it’s curent value in mysql like this:

SHOW VARIABLES LIKE 'max_allowed_packet'

You can try to change it like this, but it’s unlikely this will work on shared hosting:

SET GLOBAL max_allowed_packet=16777216;

You can read about it here http://dev.mysql.com/doc/refman/5.1/en/packet-too-large.html

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