We use some cascading/dependant parameters and, in some cases, these have their "value" property (initial/default) value unset, generally to prevent the viewer auto-run as well as to give the user a chance to select first.

The dependant parameters have their Value properties set to the ValueMember field(e.g. =Fields.value) so when the cascading parameter is selected, the dependant will have a valid value set.

However, the "missing or invalid parameter" still shows that the dependant parameter has an invalid value.For example: