so it seems like if you take Tiberian infusion as a starting item for a custom scenario, doesn't matter if it's via the prepare carefully mod or just with the edited scenario so long as it's not the nod scenario, it'll bugger your game pretty quickly via removing your hub make some of your dudes uninteractible while flickering your screen till it's a solid colour to finally softlocking.

I don't know if this'll happen with the GDI scenario or just a basic scenario but I do know that trying to play as the Forgotten will do it and yeah the only reason why I was trying to get Infusion for a Forgotten run is because the Tiberain Mutation they get seems to heal over time making them susceptible to Tib poisoning again.