After deletion, start the game to see if it generates a new save data folder. You might need to restart the game from the beginning, but this usually resolves the issue.
Inside userdata , you will see folders named with numbers (your Steam ID3). Enter each folder until you find one containing a folder called 349040 (That is Storm 4’s App ID). After deletion, start the game to see if
How to Fix "Save Data Does Not Exist" in Naruto Shippuden: Ultimate Ninja Storm 4 After deletion, start the game to see if