what i expected to happen:

some of the blocks should look like dirt in the world called: "Model Bug Test (with rp)" like it is in the world called: "Model Bug Test (without rp)" + the resource pack(Model Bug Test (the rp))

what really happened:

some of the blocks has missing textures...
(wich it shouldnt because it uses the exact same resource pack and world as "Model Bug Test (without rp)" + the resource pack(Model Bug Test (the rp)))

(the resource pack should work the same way in the two worlds...)

how to recreate:

download the file there is attached

put the "model bug test (the rp)" into your "resourcepacks" folder

put the "Model Bug Test (with rp)" and "Model Bug Test (without rp)" into your "saves" folder

now open your minecraft and go into the world called: "Model Bug Test (without rp)" and take the "model bug test (the rp)" resource pack on

as you will see everything is stone and dirt (its actually all stone but some of it is remodeled)

now take the resource pack off and go into the other world (Model Bug Test (with rp))

this world has the exact same resource pack just in the save files (so you do have the same resource pack on wich you had on before)
(it is also the exact same world)

as you see some of the stone is now missing texture...

The Bug:

im pretty sure that the thing there does this is that i have written this:

{
    "parent": "block/cube_all",
    "textures": {
        "all": "blocks/Dirt"
    }
}

(i wrote it in the "stone" model)

i wrote blocks/Dirt with a capital letter (so its Dirt instead of dirt)

but still... why is it missing texture in "Model Bug Test (with rp)" and dirt in "Model Bug Test (without rp)" + the resource pack(Model Bug Test (the rp))) ? (the resource pack should work the same way in the two worlds...)