Problems faced with Slic3r

Hi guys,

I am new to slic3r, right now i'm trying to convert 2d/3d stl files drawn by sketchup to gcode via slic3r. However, i am facing a few problems and i hope someone will help me out.
Problem 1)
Whenever i upload an stl file, there will be a thin grey line surrounding the object that i draw. May i know what is it and how can i remove it?
Problem 2)
Is it possible to convert 2D image stl to gcode?
Because i will have this error
SLIC3R ERROR:

Modification of non-creatable array value attempted, subscript -1 at /home/danisoka/Scrivania/Slic3r/lib/std/Slic3r/Print/Object.pm line 161

Thanks
Best regards
RAY

The thin gray line is most likely the skirt. This is a good thing to have if you're going to 3D print because 1) it shows the extent of your printing so you know right away if you are exceeding any machine limits, and 2) it primes the extruder so that the actual object printing gets off to a better start.

As far as slicing a 2D model, I've never tried it, but I can see where slic3r complains, because it would have no layers. Is it possible to construct a 3D STL that is the same height as your layer height?

A 2d model is by definition 2d. Slic3r does a set of check to be sure that the model makes sense in 3 dimensions. They fail on a 2d model, it's asking for a zero dimension third dimension. You can't print a zero thickness layer. Thus the error. A laser printer (2d device) would print your 2d model if Slic3r could drive it (it can't).