I discover bug.
I had only 1 empty slot in capsule kit and when i finished a mission I should get a dragonball and extra item from NPC. Bcs of no room in capsule I received only dragonball and "error" show up. I made room in capsule kit and again i talked to NPC. This time I got a dragonball and extra item. Right now I have 2 identical dragonballs.
I wasnt sure where I should write it.
I hope I helped u guys 