'SUPPersistenceException', reason: 'constraint failed'

Hi everyone,

i am developing ios native app using SUP 2.1.2

app is working fine in online mode i.e. proper login and logout many times

and in offline mode i.e. when it giving me the error

Terminating app due to uncaught exception 'SUPPersistenceException', reason: 'constraint failed'

any help