If you want a quick fix before author make an official fix here is how
Navigate to \AppData\Roaming\Factorio\mods\Darkstar_utilities_0.18.7.zip\
1. go to Darkstar_utilities_0.18.7.zip\Darkstar_utilities_0.18.7\prototype\technology.lua
find line: name = "oil-processing-2", and change it to: name = "ds-oil-processing",
2. In technology.lua Find every line where oil-processing-2 mentioned in prerequisites and change it to ds-oil-processing.
Do NOT touch this line: icon = "Darkstar_utilities/graphics/research/oil-processing-2.png",
3. if you want to see technology named ingame correctly, navigate to Darkstar_utilities_0.18.7.zip\Darkstar_utilities_0.18.7\locale\en\locale.cfg
Find the line [technology-name] and add next line so it would look like this
[technology-name]
ds-oil-processing=Darkstar Oil processing
hope it helps.
I don't use the drive Windows are on, and if i need it i would ask a friend of mine. Many thanks for the code anyway :D