Can't detach item

After finish 2nd job exam, Then I got pop up warning message (see the pict)
https://s.kaskus.id/images/2020/05/1...0513093949.png

I thought it's because my shield after that, I tried to detach the shield but it can't detach to inventory and my account is still get the pop up message.
Please help
here is the video https://www.youtube.com/watch?v=2lGe1ApYeqY

easiest way to solve this problem is :
u need to replace ur shield with a shield without str and agi requirements
like crystalline shield / ghost shield / solar shield / lobbie squidguard
u can buy that kind of shield at kiosk or find them by yourself using other character