I have a problem focusing in the live view mode with my Nikon D3200, it says "error set focus position" whenever I tap somewhere to set focus. I tried several focus settings but they all had the same problem. The green box always stays in the middle of the field and can only be moved by moving the camera itself. Motion detection works but doesn't shift the focus either. When I try using the focusing bar there's two different error messages: "Unable focus Operation not supported" and sth. like "MTP busy" (that's always gone so fast I can hardly read it). I hope it's simply because I didn't get the settings right yet and hope you can help me fix this