Single extruder MM print wont start  

Single extruder MM print wont start

I changed my nozzle to .6mm and also updated my firmware all at the same time and now I can't get my print to start. I did do a simple test print that had no issues, but this more complex print wont load properly on the printer. I've tried with binary gcode and non-binary gcode and the lcd screen says 'Print' but doesn't display an image and doesn't ever start.

Eventually after 30 minutes I got the message saying the bed temp would turn off due to inactivity. I haven't had any issues printing on my Mk4 before, any ideas?

The object I'm printing is the right side of this, combining the black and colored parts.

The Spartan UltiDex Cube Chest - All-In-One Cube System and Card Storage. Holds 1000+, 8 or 9 100 Card Commander Deck Boxes by Hugh Kha | Download free STL model | Printables.com

Tool Change GCode

{if layer_num >= 0}

    local next_filament = filament_settings_id[next_extruder];

    "M117 " + next_filament + "

";

    M600 ; change to filament for extruder {next_extruder + 1}

{endif}