Hello.
This is the Gravity Co., Ltd. Ragnarok Online: Zero Operations Team.
We would like to inform you regarding the issue reported by many customers, where upgrading using the "
Booster Power Superior Essence Enchant Ticket" is not possible when enchanting the 
Booster Power Suit item.
For items that have been enchanted using the "
Booster Power Essence Enchant Ticket",
we are currently developing a fix so that upgrading using the "Booster Power Superior Essence Enchant Ticket" will be possible,
and this is scheduled to be applied to the live server on July 17th.
Detailed information regarding the enchant will be announced through a future notice.
Thank you.
Gravity Co., Ltd. Ragnarok Online: Zero Operations Team