The Pick List Validation Constraint for a Boolean field only works if it is set as "Equal To True". It does not work for a False Boolean value. Customer has tried using the settings "Equal To" FALSE False $(false) $('False') $('FALSE') $("False") $("FALSE") but none of the above works. Some of the above generates errors on attempting to save the Pick List setting.
The Boolean logical field for most of the records in the business object had null values in it. This was because when the logical field was created in the business object, the field attribute "Nullable" was left in the default checked state. This meant it allowed Null values for this field in addition to True or False.