I posted this in the comments, but realised it would be better as a discussion so everybody can see it. I ran into a lot of problems while making my own character. Most of them were my own fault, others because of a program I used. So here is my list of everything I encountered and how I fixed it.

1. INVISIBLE CHARACTER
This happened to me, too. It was because there was one file left with the wrong name. Make sure all your esctemplate and ESCTEMPLATE files are named the same!

2. GAME CRASH
Did you alter the "YOURCHARACTERNAME.lua" file? If yes, then there is a problem with your script. Make sure you didn't forget a "(",")" or "end" or "," or something else.

3. CODE ISN'T WORKING
You altered the code, are sure you did it correctly but still it doesn't really work in game?
Are you sure everything is in the right place? Are you certain you didn't miss a "DoPeriodicTask" function where you would need one?

4. ARTWORK LOOKS WEIRD / OFF IN GAME
a) Did you edit the altas-0 & atlas-1.tex file? Better edit the character by drawing over the files in the "exported" folder.

b) Did you change the resolution of the pictures? Don`t do that unless you know how to change that stuff in code, too.

c) If you have white rectangles around your art, eventhough they look invisible in your program, make sure you delete all the layers that may lie underneath your art (the esc template for example). I found that this issue might arise with Photoshop.

5. AUTOCOMPILER WON'T COMPILE
a) Are all the folders there? Even the ones you don't need? Also check if all the images are in the folder.

b) Your autocompiler tells you an image is missing. Doublecheck. If it is in the folder, chances are that your art is anything but a 32bit png.

c) Until now I found the following problems why the autocompiler won't compile:
- Your art isn`t a 32bit png (I found that my Photoshop automatically opens and saves everything in 8bit. And even if you change the mode, sometimes it will still save your art as an indexed 8bit png).

- Your image isn't RGB (most of the times it will be "indexed color". You can use GIMP to check for files that aren't RGB or the "Properties" dialogue).

- You have multiple character mods in you mods folder. Before compiling, temporarily move them somewhere else.

- Make sure the DST Mod Tools and DST are in the same "Programs" folder.

-When in doubt, re-install the autocompiler.