Sometime you cannot alter procedure using Mysql Workbench. When you click the procedure name then nothing happen. When you see the log file you will see error message something like this :
Object name ProcedureName was not found in catalog.
If you have experienced problem like that when try to alter procedure using MySQL Workbench please do this step below
1. select * from mysql.proc;
2. Try to change definer become user@localhost or firstname.lastname@example.org where a.b.c.d is the ip address (host) where you connect to database.