Madclowns Mod https://mods.factorio.com/mod/Clowns-Nuclear, disables the Kovarex enrichment process from being research, this prevents research into your Uranium crystal processing.
[did turn that mod off and found its want the cause and so i am now checking through my current mods that edit Nuclear power/ research to pinpoint the mod]
kinda halting my research into your later techs.
my suggestion is:
A) work around to prevent disable of tech
B) some kinda combability with the clown tech, like a -IF this, then switch to this research
