go into your playersave.java and search " character " or "character file " or something along those lines and it should give you a result to your path.
Ex: mine is
characterfile = new BufferedReader(new FileReader("./data/characters/"+playerName+".txt"));
So it will try to save the character file in my data folder and it will look for a file named "characters" and it will put the saved character account in there. So make sure you put the file in the right place.
Hope this helps you a little bit more in fixing the problem.
Also if you google " character saving rsps pi " there are a few posts with other fixes and suggestions.