Subject can't log-in as user account firebird

I changed firebird to #: passwd myfb at the command-line.

At su firebird I get:

su: failed to execute /bin/nologin: No such file or directory


not sure what I am doing wrong. I am using firebird 2.5.4 fedora xfce classic.

Please assist!

Addendum: with the root log-in I can select data from sample db. I
have SYSDBA account setup with a password and will do a new account once I get this
straightened out.