Hello, This is the Gravity Ragnarok Zero Operations Team.
We would like to inform you that the responsible department is currently investigating an issue where, for some payment methods, a login session expired and payment failure screen appears during G-Cash charging.
Please be assured that there is no actual issue with payment processing or G-Cash charging, and we will provide further information regarding this matter through a future notice.
Thank you.
Gravity Ragnarok Zero Operations Team