I thought I would share my findings on the site so others might have a heads up to the mount problem . I called Panasonic to lodge a complaint about this lens being very tight on the EM 1 Mark ii. They directed me to Olympus stating this was their problem. I called Olympus and they agreed it was in fact a problem with this particular camera. They arranged for me to take the camera to a service center in NJ to have the springs adjusted on the camera to accommodate this lens..wow. Talk about quality control. I may have to switch back to my old system..never ever have I have any of these problems on my Nikon's. On a positive note Olympus's customer service is top notch.. They actually answer their phones in record time and give good solid advice.