Can't Open Premium Surprise Style Box

Hello, I'd like to ask help from all of you readers...
The problem goes like this...
It's been days since I got a Premium Surprise Style Box from a monster drop. I took it, and of course it's in directly to Cash Inventory. But the problem is, I couldn't open that box! I tried to open it many times (by double-clicking it of course, I don't know if there are any other ways...) but it won't open! Anyone knows why? Have you ever experienced this and it's fixed? Or maybe it's a bug?T_T

Thank You

You have to move it to your CS inventory first. As in, go into cash shop, double click it to move it into CS, then double click it again to open.

You have to move it to your CS inventory first. As in, go into cash shop, double click it to move it into CS, then double click it again to open.

OMG! Is that what the people were saying??? I thought to Cash Inventory...
Thank You so much, happylight !!!!!