I am trying to send complex parts to someone and getting the following error:

Ship cannot accept shipment [ 217 / 180 Cargo Space Used ]

This is a bit odd since complex tech doesn't take up space.

but he has -37 space avalible so send when he has one or more space left.

Yup happened when I tried sending some EM to someone. I can only guess the ship has to have some space to recieve even if though special items take up zero space.

if your cargobay is overfilled, your cargobay door is held closed by the pressure of all the cargo jammed in there pushing up against it.... so u can't open the door to let in a letter-sized envelope containing 25k exotic matter...

(battle rewards come in through the passenger's door I guess.. that's how you're able to fill your ship beyond capacity)

wait how does it get overfilled, i never heard of that happening

most common reason is changing class

an even more common way of overfilling is as i said.... battle rewards from killing NPCs.... they'll ALWAYS be added to your cargobay, even if you're full

okay