calamity NPC's null reference exception

whenever I try to turn on the calamity mod in the downloaded mod menu it gets pretty far then says this. I've uninstalled calamity, I've uninstalled TML, I've uninstalled Terraria and it still wont fix. I've looked online for things and people say to come here for answers. I've had this problem for about 2-3 weeks at this point and I just want to play calamity.