Curiber

I just tried this yesterday... so you get a magic box and you rezz it on the ground. You have to keep it there... I couldn't find info either so I'll tell you what I gathered from testing... you rezz on the ground then do edit > contents and drag the item in. I THINK you can only sync THAT box once (you can't add items to it after you've listed the item(s) in it.. it wouldn't let me anyway but I could be wrong)... so then you go into your mp and click sync magic boxes... it should be there. You have to be allowed to use scripts where it is... you can't use magic boxes from your inventory.

Are you trying to upload the mesh DIRECTLY to the merchant box? You need to import it and get it in your inventory first... magic boxes are still the only method to sell no copy items in the marketplace. Is it a no copy item?