trying to mark a full name with "*" if the member field is valid. Incorrect result
If ( IsValid ( Member ) ; "*" & Husband_Name_First & " & " & Wife_Name & " " & Name_Last ; "" )
What is your definition of "Valid"?
It might not be the same as FileMaker's definition of the same. "IsValid()" returns true if the value exists and if (for calculation fields, there's no calculation error) and (for fields with special formats such as date/time/timestamp) no data entry error.
So if your calculation was; 25 / 0, IsValid would return false
If you entered 13/13/2017 for a date, IsValid would return false
usually the goal of data input is to come back to the data layer with valid results, not coming back with data flagged as invalid. You might want to reconsider your whole data flow.
get data into globals
exit loop if data ok
What data do you enter the Member field for valid members?
Empty is also "valid" in FM, so if you want to treat empty as "not valid member", IsEmpty ( Member ) would be.
Retrieving data ...