Is anyone unable to equip new hats/items?

Same but i cannot equip itmes, help

I have the same problem! now my alien is NAKED! 

I have also been having issues equipping and unequipping things. Some items work, most don't. I can seemingly unequip most items just fine but I'm at a loss as to why. There also appears to be a few duplicated items, such as the valentine's day shirt

A lot of stuff show up but you don't actually own it. You try to equip it but you cannot save because you don't actually have it in your inventory. You have to spend the arp in the marketplace if you want to use that specific item.

Besides the one you get from free from AWASCC or Calendar, if there shows up many others that you never seen, like Kokuei said probably it's just a bug showing unowned items there.

Even once I got ARP Boosters as equipable parts for Avatar XDD

Anything you have redeemed in the marketplace should be wearable! There was a bug a while ago that added items to your profile that do not save, so those items won't work, but the customization should be working correctly.

I had once Valentine's Day items listed, but they wasn't equipable. Until I recognize I hadn't own them. It was a bug.

I bought a costume over a month ago. It took the ARP but never gave me the costume.  Not going to buy any more.