Hello, I am brand new at 3d printing I have a cr10 pro v2. It is printing excellent from the first print using files that came with the software, opening, moving and general print. Spent a while on setup and leveling a couple of hours and as I said prints great. Files that I downloaded which are stl files act the same slice, show up as stl and gcode save to sd card , move card to printer and they are there. Some act the same move, slice, save to sd card do the same but don't show up on the print cue on the printer. Thanks for any input I really appreciate the help.