Do following:
* Verify that your printer tray is properly set.
* Remove the object they they are placed in front of printer.
* Clean if there is any piece of paper or something else in printer.
* Clean the encoder strip with soft cloth.
I hope with these points your issue might be resolved if not then check [http://guideusermanual.com/product-name-pixma-mg6350-manual&po=157064&lang=English|Canon Pixma Mg6350 Manual] to troubleshoot your printer.