I can't exchange sage crests

[winniethepoop]

Hi,

I have 250 sage crests to Exchange but when i try to Exchange I can't add them to proceed to Exchange .I am level 65 . I have to be a certain level to Exchange ? I am hunter with fighter as subclass. I have to complete the crafting order of zieg ?If yes , how i can do it , i don't know how to complete it , so in a room in craft section iI need a lot of material that obviously i have no idea where to find. I am trying to Exchange a wired lance . Any idea of how to solve my problem ? Any help is gratefully welcome .
Thank you in advance

[Loyd Azakuya]

You probably have your inventory full, you need to make room for the item