I bought the thingie, and I read that one is supposed to set the camera to ”no lens“ in some obscure menu option. I can't find that, and wonder if anyone knows how it is supposed to work on an E-PM1.
You don't need to do that with Olympus cameras. My dad got the 15mm for Christmas and it works fine on my E-M5 and his E-PM1 without any setting of options required. I believe the Panasonic cameras need you to set this option, but you should be fine with your PEN. Enjoy your new lens!
I'm getting there...