As usual error messages tell you something. Read them instead of just acknowledging them. If you don't understand them directly, google them or find them in the documentation.
In this case probably the error message told you that the evaluation of parameter.pm resulted in a false value, which should not be (although I don't have the slightest idea why this was built into the module system). Just add as a last statement anything that results to true, usually everyone just adds
1;
as the last line of a .pm file
