less-science-packs/data-final-fixes.lua:54: attempt to perform arithmetic on field '?' (a nil value)
stack traceback:
less-science-packs/data-final-fixes.lua:54: in main chunk

What other mods do you have installed? I haven't added any support for other mods that add new science packs yet, so that is likely where the crash is coming from.

(I've added to the info page here clarifying that only base game and space age science packs are supported for now.)

various planetary mods that add their own packages to the game are most suspicious of moshine due to the ii models instead of packages