Bukkit

i enchanted once at lv 30 to test out in both creative and survival, enchanted second time both creative and in survival and both times grayed out
". . . ?
Limited Enchantability" 

i thought maybe its something in the config that i need to turn off to make it so ill be able to view it and have it not grayed out if i have the required xp, im able to click it and it removes my xp and it adds the enchantment but why is it grayed out even when i add the lapis lazuli its still grayed out but i can still click it and then it removes my xp if i have it any idea?

ill post picture 
https://imgur.com/a/uaiwknB