Items is lost if one of the players has full inventory
If i have 2 slots left, i trade someone and he gives me 3 items - then the 3rd item is lost.
Neither him or me have it.
Obvious solution is to move a large amount of your inventory into a backpack before you start trading !  If you dont  use backpacks then leave plenty of room in your inventory, except for weapons (where there is a slight glitch) you can stack most items to the 100/1000's (with stack size controller plugin) so there should not be any difficulty.
Obvious solution would be to make trade plugin say "Trade not done, inventory full".
But yes of course, its up to the players - but i have had ppl complain about it, mistakes can happen - but plugin should catch those mistakes :)
We get the same issue with players.
It doesnt disapear, it drops into a backpack which unfortunatly, clips through foundtions ect. 
I have collect a number of players dropped backpacks after a failed trade. 
A check to see if inv is full or for the backpack to not clip through the floor when spawned would be great :)
NoiZeX
Obvious solution would be to make trade plugin say "Trade not done, inventory full".
But yes of course, its up to the players - but i have had ppl complain about it, mistakes can happen - but plugin should catch those mistakes :)

should be a way to do it, when using kits plugin it wont let you redeem a kit if you dont have enough room,

Will this plugin ever patch this issue? It is the number one issue reported by players.

Expecting "players" on Rust to catch this issue is idiotic, especially if they have a 15 slots free but 17 in a trade. Very hard to notice, and with no warning, they go straight to staff about the issue.

A fix would be more than welcome and I would be very thankful.