I created a simple one character texture pack, replacing all the files of Dave with custom files of precisely the same size.
Problems.
1) When I change to this test texture pack, the screen reloads and the font disappears. I can't get the font back without restarting the game.
2) The custom image files are not recognized. I have a Dave as my character but instead of my custom images, I still see Dave.
3) When changing back to the blank option for a texture pack, the same thing happens as 1). The Font disappears and I have to restart the program.
In case it matters, I got my copy from Steam and then used the game's autoupdater, yesterday.
I really don't like any of the sprite graphics for the human characters, I'd rather use 16-bit replacements, and work on replacing the rest with corresponding style, but I can't.
http://i.imgur.com/VN6vJ.jpg