Stitched terrain/items appear on my desktop.

Upon loading the game, I get a stitched_terrain.png file created on my Desktop, I know that file is unused as I can delete it during runtime with no consequences, also when switching the texture pack (only tried switching to the incompatible ones) the file stitched_items.png file is created on my Desktop, but it looks messed up(textures atop each other), upon closing the game, both those files stay on my Desktop.