I can confirm that this is true – if you were quick enough to get your Tuscan wedding tent out of the gift box and place it on your farm – you will be getting a white screen or a page cannot be displayed error.
I just logged into my daughter’s account because I knew she’d not played today and therefore would not have had the opportunity to place the tent – and voila! I’m in. It’s not your computer, it’s not just your account, it’s not cookies or cache, it’s not your particular country or friends group, it’s not any of your other programmed… it’s Zynga! They’ve done it again this time in the biggest way I’ve seen since starting to play.
They wonder why people take every opportunity to hack/crack the game!