I enabled security on Jenkins and added myself as the only user. After clicking on \"Save\" it brought me back to the log-on screen without asking me to create a password. N
Fine Jenkins_home open config.xml inside home directory. find useSecurity tag - and set it default. restart Jenkins. Open Jenkins (should take you inside with out a user name and password) -- go to manage jenkins -> Global Security -> Enable Sign up -> sign up a new user -> once user is sign up - login with that user and finally enable login and restart your jenkins.