I uncovered the mosaic and placed a totem in the center and the last piece of the gong was reveiled. I put one of my villagers on top of it and he picked it up. I hadn't realized that I put an old villager on it....meaning he would go really slow. I went away from my computer for a little while....came back and the gong piece is gone. And the villager that had picked it up doesn't have it. And it says the puzzle was never solved. I have tried the process all over again but of course the gong piece doesn't show up! It was my LAST puzzle to solve! I'm so frustrated! Does anyone have any ideas?

Quit the game, start it again and repeat the puzzle solution.

Oh thank goodness! It worked! Thank you, Thank you, Thank you!!