I really need some help with my monoprice select mini v2. I am having a hard time getting it to print anything. It will print the cat.gcode sample model just fine. I've downloaded a bunch of stl models from thingiverse. I've only gotten 2 models to print so far . One is an adapter for a 40mm gas mask. I opened the stl file in cura then loaded the gcode profile from the cat model. It printed fine. I've tried this same technique with my other models and when I go to print, the printer does nothing. The progress bar on the front of the printer begins moving like it's printing but the printer does nothing. What am I doing wrong? I'm getting very frustrated.