Probably no one have informed u of this:
https://mods.factorio.com/mod/Krastorio2/discussion/5fc532179f810e5bbbbe81d2
I think u have moved/removed that tech for match some different tree sturcture, u should change in that t&t definition the new technology, or remove the t&t

+1

Came here to say this

I made a patch specifically for K2 that replaces the K2 fusion/antimatter with RFP/W fusion/antimatter. It can be disabled with a setting, so do that for now. I'll fix it asap, couldn't do it earlier bc of school.

Fixed in 1.3.12. The t&t's still there even though the K2 fusion reactor isn't, just in case another mod needs to access it for whatever reason.

Yay thank you!