Getting an "Authentication token manipulation" error when trying to change my user password - Ask Ubuntu

i logging in ubuntu server using username. once logged in typing passwd command. entering new password second after getting following error messages:

passwd: authentication token manipulation error passwd: password unchanged 

what wrong here? how can change password otherwise if don't have access server physically, i.e. connecting remotely ssh using terminal.

if insert wrong passwd

$ passwd changing password rinzwind. (current) unix password:  passwd: authentication token manipulation error passwd: password unchanged 

you error. if sure inserted correct one, error might show if using shadowed password files , shadow doesn’t have entry user (basically/etc/passwd has entry user, /etc/shadow not).

in order fix this, can either add entry manually (make backup first!!!) or recreate shadow file pwconv (manpage).