In startup.. yes. Also gives you an error about the exception. It is a mod refusing to start.
No, it isn't refusing to start. It is crashing the whole game because greg feels like it.
It's not going "TiC is overriding recipe."
"Not loading Gregtech with overriden recipes"
"Please uninstall TiC to use Gregtech"
That would be childish, but not as bad as what he's done.
It's not required.
It's because he enjoys acting like a goddamn toddler.