add a prefab or a loot container to the map

When I do that in rustedit, save the map and upload it to dropbox and start the server so have all vendors changed to selling the same things, thats includes the horse vender in the warehouse, are I missing something here ?

if I upload the orginal map and start the server so does all vendors work as they should, so its when i have edit the map

That happens because you modify the map, I give the code but if you modify the map and those modifications arise, I cannot do anything since the maps are echo so that the Owner upload it to their smart servers to work, but if you modify it with Rust Edit, I cannot do anything,
The only solution is that you believe your own sellers so that that does not happen to you.

But if you get to my discord you can get the sellers of a URL and also dodne are my future projects

https://discord.gg/WCbpdNYYmj

Changed Status from Pending to Closed