This might work, it has worked for some in the past, but does not always work. No guarantee.
Move your save game from %appdata%\7DaysToDie\Saves\*YourWorldName*\*YourSaveName* to your desktop.
Then create a new game with the same world, name, size, and seed as the game you just moved. If it's a random
gen world and you don't remember the settings, they will be in the "map_info.xml" file in your GeneratedWorlds folder.
If it's Navezgane or a Pregen, use that map.
Start the new game, then stop it and close 7D2D. From your backup files on the desktop, copy the "main.ttw"
file and the files in the "Player" folder to the new save & player folder that you just created.
Try to start the game.