if you use one of the characters you crafted and dies you lose your body idk if it is a bug or what.

Do you mean your inventory disappears? Let me try to be clear:

• Craft and place a new character.
• Switch to that character.
• Craft some electronic circuits.
• Get killed somehow. You get put into your original character.
• The electronic circuits are missing from your inventory.

Where did they go? They are stored in the dead character body. Am I understanding correctly? If so, this is intentional behavior. Crafted thingies stay in the body that held them, even unto death.

• Craft and place a new character.
• Switch to that character.
• Get killed somehow. You get put into your original character.
• you cant pick up that body into your inv

Oh, I see. That is not intended behavior. I will look into this. I haven't played factorio in a few months, so there might be some new bugs with my mods.