Tried the isRemote check, doesn't seems to fix it
The entire console after i terminate the game was this:
I did see something like:
Exception caught during firing event net.minecraftforge.client.event.RenderLivingEvent$Pre@1400b97 (number changes everytime, I got this through a screenshot).
It has something to do with the dorender part, because it works if i just use event.setCanceled(true)