i purchased a mc 9000 used online (well not used at all since everything was in its orginal packaging and unopen). i got it started and was sewing for awhile until the machine didnt feed the fabric any more. I got the message "Safety Warning *is something stuck in machine? *is cloth too thick? *is needle bent?. i checked everything and rebooted the machine. then it would stitch 5 times and same message pooped up. i took everything from the bobbin holder out and used my husbands air compressor and blew anything out and re thread it. then it did the same thing again. it acts like the feed dog wont feed the fabric so it just keeps sewing in the same spot then getting knotted underneath. Any ideas as to what to do to fix this. i have a few days to get it working or im sending it back for a refund.