UOX3.org

how can i make a container be able to hold unlimited weight/items

I think they already can. But if you're thinking of making something like a "bag of holding" which players can use to hold infinite amount of weight - that won't work as the maximum weight they can carry depends on their total strength multiplied by the WEIGHTPERSTR setting in UOX.INI, plus 40.

i get an error messages when i try to put more than 3 spawners in a bag, says the container cannot hold more items/weight