I tried resetting it and re-adding all my decorations but it keeps saying 'too many of X' even though none of them are showing up - I'm using Chrome and I don't normally have issues with this browser?

Hoping it isn't just user error .__.;

I am having this issue as well. I'm on Safari on my iPad. It was working fine a couple of days ago.

Cleared my cache again and everything seems fine now! :)

There's more info here: Lumi trees missing, returned to add more ornaments