So after I got the Platinum Chip from Caesar I brought it to Mr. House and he took it from me and told me to go to the fort into the secret bunker. I dont have the chip anymore and he doesnt seem to be able to give it back to me because you cant talk to Mr. House, he just tells me to go to the fort. I seem to have lost my Platinum Chip. Ive tried everything to get it back, caesar doest have it on him, i looked around the lucly 38 for it, even putting the Platinum Chip that came with my Fallout in the disc tray didnt fix it. Is there anyway i can continue with the House Always Wins quest?

I think Mr. House is supposed to put it back in your inventory after you speak to him and tells you to go to The Fort. If you checked and it's not there and you can't get into the bunker then you have to go back to a previous save and hope nothing screws up again

Just reload the game,i found this worked for me.i'm holdin it in the inventory,don't reckon it'll be long before i encounter another glitch that makes it vanish again though!

After i gave Mr, House the chip i ran off and did a ton of exploring and quests. To load a previous save would put me back more than 20 hours of gameplay. Its probably not worth it, ill just kill him and finish the ncr questline instead.