Why cant i upgrade my minion

[Mechuw]

everytime i try to upgrade my coal minions, it brings me to a menu where it asks me to confirm whether or not i want to upgrade it. When i press confirm it doesnt really do anything and closes the menu even though i have the said amount of enchanted coal in my inventory. Please help.

 

[Jesse531]

You have to make sure you have the required items in your inventory while doing it.

 

[Minecraftian]

It currently appears to be bugged, I've had the same issue. Make a bug report here, it's the best way to make sure it gets fixed.