I own a Nikon D90 for a few weeks but since almost the beginning, it crashes regularly. The message "ERR" will appear randomly without it disappears. I am forced to shut it down, several times to get everything in order.I even ever had to remove the battery to remove the problem. Several reset did not change. The problem really appears randomly during a photo shoot, with or without flash.It is coupled to the 18-105 VR lens. No game between the lens and the camera and the contacts are very clean.I read that some people had encountered this problem: the set this down? Knowing that the error is not reproducible voluntarily, I wonder how the solve this issues. Thank you all.