You have wood and steam science, so I think Lignumis?
Same here, I get the same error. Enabling Nexus, atan-nuclear-science and cerys-and-nuclear-science, but DISabling Lignumis doesn't crash Factorio. So I believe this "new" error isn't necessarily connected to atan-nuclear-science. (OP doesn't seem to have Lignumis since there's 14 packs listed, not containing wood and steam science packs, and we got 16 including those both).
Lignumis messes a bit with technologies and adds their wood and science packs to many techs generously, which I don't mind. But either
- Lignumis automatically adjusts the valid input of labs (to add wood and steam packs as valid inputs) and maybe doesn't recognize that it would have to do so with Nexus' Omega Lab, too,
- or Nexus would have to add wood and steam science packs as valid inputs if Lignumis is activated
I'll post in Lignumis, maybe they can offer advice. Edit: https://mods.factorio.com/mod/lignumis/discussion/6855721fe542593fe277df9b
Edit: yeah, if I hack the two packs into the Omega Lab, Factorio starts without crashing (and all mentioned mods enabled):
...
inputs =
{
"wood-science-pack",
"steam-science-pack",
"automation-science-pack",
...