Password policy without limiting the age

Password policy without limiting the age

I have question about password age in policy.

I tried to make the policy restricting to have numbers and special characters, without password age.
But when I set the password age as blank, message said " Unable to process your request". And when I set 0 for password age, "Password age should not be less then 7 days.".
So now "password age"is a mandatory in the policy and restricted to 7 -120 days?