Try the reset noted at https://www.google.com/search?q=Lumix+GX1+reset.
Specifically noted at http://fourthirds-user.com/forum/showthread.php?t=11052
also, is the memory full?
Toward the end of a recent vacation, my Lumix GX1 suddenly stopped operating. The battery had power, and the main screen appeared, but I could no longer focus and take a picture. Also, I could not access any of the menus and so could not view photos. The camera told me to reinsert the card, but that didn't make a difference. Now that I'm home, no photos are "found" when I try to upload them to my PC. Help. Thank you.

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