parse.com - Android Parse "invalid session token" error -

i new android , stuck on seems simple problem fix don't know doing wrong! need sign user, reason e never equal null , therefore goes straight else part gives me invalid session token message. here code signup part, looked @ thousands of times!:

protected edittext musername; protected edittext mpassword; protected edittext memail; protected button msignupbutton;    @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_sign_up_manager);      musername = (edittext)findviewbyid(r.id.usernamefield);     mpassword = (edittext)findviewbyid(r.id.passwordfield);     memail = (edittext)findviewbyid(r.id.emailfield);     msignupbutton = (button)findviewbyid(r.id.signupbutton);      msignupbutton.setonclicklistener(new view.onclicklistener() {         @override         public void onclick(view v) {             string username = musername.gettext().tostring();             string password = mpassword.gettext().tostring();             string email = memail.gettext().tostring();              //trims spaces             username = username.trim();             password = password.trim();             email = email.trim();              //if 1 of text edits empty send them message                                    title ok button.             if(username.isempty() || password.isempty() || email.isempty()){                 alertdialog.builder builder = new alertdialog.builder(signupmanageractivity.this);                 builder.setmessage(r.string.signup_error_message)                         .settitle(r.string.signup_error_title)                         .setpositivebutton(android.r.string.ok, null);                  alertdialog dialog = builder.create();                 dialog.show();             }             else {                 setprogressbarindeterminatevisibility(true);//the progress circle active.                  //creating new parse user.                 parseuser puser = new parseuser();                 puser.setusername(username);                 puser.setpassword(password);                 puser.setemail(email);                  puser.signupinbackground(new signupcallback() {                     @override                     public void done(parseexception e) {                         setprogressbarindeterminatevisibility(false);//the progress circle not active.                         if (e == null) {                             intent intent = new intent(signupmanageractivity.this, loginmanageractivity.class);                             intent.addflags(intent.flag_activity_new_task);                             intent.addflags(intent.flag_activity_clear_task);                             startactivity(intent);                         } else {                             alertdialog.builder builder = new alertdialog.builder(signupmanageractivity.this);                             builder.setmessage(e.getmessage())                                     .settitle(r.string.signup_error_title)                                     .setpositivebutton(android.r.string.ok, null);                              alertdialog dialog = builder.create();                             dialog.show();                         }                     }                 });              }         }     });    } 

please help, in advance!

first post here had same error. correct me if wrong believe issue me create user once , invalid session tokens afterwards. think due fact "session" on parse website's end still logged in though can close , re-run app on end.

by putting following code before try create new parse user fixed issue.

parseuser currentuser = parseuser.getcurrentuser(); currentuser.logout(); 

hope helps. cheers!