Go to the darkstar zip mod, prototype, recipe.lua, search for dark-matter(there will be a lot of it, search for the one that makes the dark-matter) exchange the false to true and it will appear.(It worked for me.)

the issue is with bob's mods removing the technology effect that darkstar adds to unlock the recipe. this needs to be fixed by bob.

having bob's mods {bob's assembly, specifically}
prevents dark matter and antithetical matter recipes from being able to be unlocked (the mod removes/alters technology and prevents the recipe from being able to be unlocked.)

one method of verifying this is the case is by adding "? bobassembly >= 0.16.1" to the info.json of darkstar utilities. this forces darkstar utilities to load AFTER bobassembly and we see the impact of it reverse (darkstar's recipes are fixed, but now we've broken recipes from bob's assembly: namely the oil refinery 2, and probably others as well).

1 solution involves darkstar utilities setting an optional dependency for bob's assembly but ADDING effects to the technology rather than overriding it completely. this keeps both mods functional. another solution involves bob's assembly doing the same, but pointing an optional dependency at darkstar utilities and changing the way it impacts technology so the recipes aren't perma-locked behind technology that has had the recipe-unlock effects removed.
and final option is simply setting the recipe to not be hidden, and thus craftable from the beginning of the game. this is not necessarily the "best" way, but it is the quickest way to fix compatibility between the two mods. An even dirtier trick is to add a data-final-updates.lua, have it check for bob's assembly, and then change the hidden-flag to unlocked from the start if that other mod exists.

--edit bob's assembly oil-refinery.lua to read like below and it'll fix this issue

if not data.raw.technology["oil-processing-2"] then
data:extend(
{
{
type = "technology",
name = "oil-processing-2",
icon = "base/graphics/technology/oil-processing.png",
icon_size = 128,
prerequisites =
{
"oil-processing",
"advanced-electronics"
},
order = "d-a2",
upgrade = true,
unit =
{
count = 75,
time = 30,
ingredients =
{
{"science-pack-1", 1},
{"science-pack-2", 1},
{"science-pack-3", 1}
}
},
--[[ --commented out. we'll add the recipe unlock later
effects =
{
{
type = "unlock-recipe",
recipe = "oil-refinery-2"
},
},
--]]
}
}
)
end
--add effect: unlock recipe regardless of which mod is adding "oil-processing-2" technology
bobmods.lib.tech.add_recipe_unlock("oil-processing-2", "oil-refinery-2")

Factorio doesn't like having multiple mods add technology with the same name, but unfortunately this does happen. the best thing that can be done is to set the standard method for adding technology to be as above:
1) A built in check that the technology of the same name doesn't already exist (isn't already added by another mod)
2) If it doesn't already exist, we initialize it.
3) After it's initialized, we ADD effects as desired.

where do i go t find bob's assembly oil-refinery.lua on my pc

The same problem appears to exist for 5dim's mods, which adds mk2 and mk3 oil refineries as well and it too does not show dark matter recipes.

I've now fixed bob's compatibility, 5dim's compatibility, a few typos and productivity module availability for intermediates.
Do you have a git or similar somewhere for pull requests?

@Berserker55 where can you get your fix?