Been playing for a few weeks. I've been trying to add components to varies pieces of equipment but when I right click per the instruction instead of being able to add the component to the item the whole stack disappears. I had 29 pieces of plate that all disappeared when I right clicked.

When you do that while a second window is open, like from a vendor, the stack gets sold.

Yup, beware, in GrimDawn vendors are nasty greedy :)
Think this almost bug as a background feature :)