First of all, make sure you put the picture as (png. or jpg.) file. It's written in that 'preset_12' note(word document).
Also make sure your picture is 513x513 or 512x512. When you go to presets in your game, If the mane doesnt show up in (I guess) preset_12 as you said, try clicking on another preset and then back to preset_12. It happened to me few times.
If nothing of this helps, try contacting one of the staff members.