I have a problem. I have armor with slots, but i cannot upgrade with copper plates. Why?
For mechanic some armors have exact amout of maximum slots and it can be 0-2 1-2 2-2 first number is how much slots you have opened and second is exact number of maximus slots for exact armor.
Some do not have it
And as Fairy equipment there is exactly all 1-1
Tried on my save and changes for upgrade and slots saved and slots do not dissapear. Try my save
You playing right now on 0.6.0.1 version of game?
Checked and all slots are still there before upgrading.
upgraded with copper and iron and saved game, changes saved, not upgraded armors still have not used up slots.
But again i from the start not so lucky for slots(
And forging mastery right now at 30+ i think.
try my save there is enough of materials to try it.
P.S. Do not use arrows quiver in the north exit of Arenfield, it deletes all upgrades and delete all slots i think.