Error Domain=Parse Code=209 "The operation couldn’t be completed

I installed the ParseStarterProject swift version and created a new user with the following code:

var user = PFUser()
...
user.signUpInBackgroundWithBlock...

Then I ran the project again without doing anything I get the following errors:

2015-03-26 09:49:25.485 ParseStarterProject[14768:199520] [Error]: invalid session token (Code: 209, Version: 1.7.0) 2015-03-26 09:49:25.489 ParseStarterProject[14768:199521] [Error]: Failed to run command eventually with error: Error Domain=Parse Code=209 "The operation couldn’t be completed. (Parse error 209.)" UserInfo=0x7fcda3cb6680 {error=invalid session token, code=209}

what have I done wrong??