I've played up to "The Abyss" venue, and I've noticed a few problems so far.
1. At one point, the game notified me that I had unlocked a skull-shaped microphone, but when I went to equip it in the rock shop, it wasn't there.
2. On two occasions now I was notified that I had unlocked a minifig (one being "Race Team Blue" and the other "Capt. Jack Knife") but when I went to purchase them in the rock shop they weren't there.
3. Items in my rock den spontaneously change color for no particular reason.
Can anyone help me with one or more of these problems?