create user ‘test’ @’ % ‘identified by’ test ‘;
create user ‘test’ @% ‘identified by’ test ‘;
display ERROR 1396 (HY000): Operation CREATE USER failed for ‘test’ @ ‘%’
check whether there is this USER
select USER from USER;
found no such user.
remember you deleted this user last time.
flush privileges may not be flush;
, ERROR 1396 (HY000): Operation CREATE USER failed for ‘test’ @ ‘%’
drop USER ‘test’ @ ‘%’;
drop USER ‘test’ @ ‘%’;
failed for ‘test’ @ ‘%’;
drop USER ‘test’ @ ‘%’;
flush privileges;
create user ‘test’ @ ‘%’ identified by ‘test’;
create user ‘test’ @ ‘%’ identified by ‘test’;
success.
Assume the user is there, so drop the user
After deleting the user, there is need to flush the mysql privileges
Now create the user.

http://stackoverflow.com/questions/5555328/error-1396-hy000-operation-create-user-failed-for-jacklocalhost