ERROR:PHYSICS: Physics world buffer full, world could not be created.
i have a 1-1.collection in a omega_colony.collection inside a game.collection in a main.collection
between these have a inventory.collection and a player collection and a cut_scene.collection
all collection proxied
I believe you can solve this by increasing the world_count of the physics settings in your game.project.
As @amel pointed out, this is how you would fix it. 
The reason you get the error, is that Defold will allocate a physics “world” for each collection (proxy) you load. This means that each collection has its own physics world, collision objects will not interact with other collision objects from different collections.
Defold is built on the idea that it should preallocate as much as possible up front, to avoid doing memory allocations in runtime (which can cause memory fragmentation and some under some scenarios loss in performance). We try to have “sane” defaults for these values, for example physics.world_count is set to 4 by default, meaning there can be a maximum of 4 physics worlds in your game. However, this value can be changed, so if you have more collections that need to have physics simulation, just up that value! The implication is that the game will allocate a bit more memory to handle this.
And if you aren’t using physics at all in your game, you can even lower this value of course, to shave of some runtime memory usage. 
ok thanks