@NotJezzy so it completely closes, the bootstrapper cmd window does not remain open? Sounds like broken files then tbh. Try this https://forum.plutonium.pw/topic/6353/how-to-repair-your-t6-installation
It could also be your antivirus falsely detecting the bootstrapper: https://forum.plutonium.pw/topic/8546/why-is-my-antivirus-saying-plutonium-is-a-virus-solution