Information
Defines the minimum number of lower case alphabetic characters in a password.
In setting the minloweralpha attribute, the password must contain a lower case alphabetic character when it is changed by the user.
Solution
In /etc/security/user set the default user stanza minloweralpha attribute to 1 :
chsec -f /etc/security/user -s default -a minloweralpha=1
This means that there must be at least 1 lower case alphabetic character within a password.