Hello. I don't understand what I'm doing wrong. I connected the fuel rods to the interface, put the fuel elements there. But they don't load themselves. I did it manually, but the tube doesn't heat up. The control rods also don't work. I fed a signal through the constant combinator "S" - also nothing. Not part of assembled reactor.

You have to place a reactor interface down, that will let you assemble your reactor. Everything has to be touching, so no air gaps. In the fuel rod there should be two sliders and an item button, the button lets you choose the fuel and the sliders let you choose the min and max request. If it has less then the min request, it will fill up from interfaces

Error while running event control-your-rods::on_tick (ID 0)
invalid key to 'next'
stack traceback:
[C]: in function 'next'
control-your-rods/scripts/cooling-towers.lua:24: in function 'update'
control-your-rods/control.lua:68: in function <control-your-rods/control.lua:66>