From the canon support page, that error code 6000 list a couple possibilities such as a something preventing the feed tray from opening either by blocking the printer, an unseen friction, and a possible paper jam inside the printer.
http://www.canon-europe.com/Support/Consumer_Products/products/Fax__Multifunctionals/InkJet/PIXMA_MG_series/PIXMA_MG6350.aspx?faqtcmuri=tcm:13-986898&type=faq