How to Change the Minecraft Main Menu Background Image
Where the Mod Looks for Your Image
Simple Menu Mod replaces the vanilla panorama with a single flat image. You supply that image yourself, so the first step is preparing a file the game can actually read. Use a standard image format (PNG or JPG) and match the aspect ratio of your game window, otherwise the picture will stretch. A wide, landscape-oriented image works best.
Pointing the Mod at Your File
1. Open the mod's config screen from the main menu (there is a button added for it) or edit the config file directly.
2. Find the background option and enter the path to your image. Place the image somewhere stable, like a dedicated folder inside your game directory, rather than a temporary downloads folder.
3. Save the config and return to the main menu. The background should swap immediately; if it does not, fully restart the game so the menu reloads.
Fixing Common Problems
If you see a black or missing background, the path is wrong or the file is unreadable. Double-check the spelling and the file extension. If the image looks squashed, your aspect ratio is off. Keep the image reasonably sized so the menu does not stutter while loading.