Problem with .jar working with netbeans

Hi, I made an application that saves and loads files, the problem is: when I run the program from netbeans, it works fine, I can save information and load files, but when I create the .jar and execute it, it doesn't save and load the files the way it does trought netbeans, it saves and load incorrect data

Any ideas?

Few questions to you,

1. What you mean by incorrect data? How you find that?
2. How you run the build package and did you comes with any error?
3. Can you show what you've done here?